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TNT 

TRINITROTOLUENES 



AND 



MONO- AND DINITKOTOLUENES 

THEIR MANUFACTURE 
AND PROPERTIES 



BY 

G. CARLTON SMITH, B.S. 

Instructor in General Chemistry, School of Applied Science, 
Carnegie Institute of Technology, Pittsburgh, Pa. 




NEW YORK 

D. VAN NOSTRAND COMPANY 

25 Park Place 

1918 



. 



Copyright, 1918, by 
D. VAN NOSTRAND COMPANY 



AUG 21 1918 



PRE8S or 

BRAUNWORTH & CO. 

BOOK MANUFACTURERS 

BROOKLYN. N. V. 



/ 

5031 74 

' \ 



TO 

WHOSE SACRIFICES AND LOVE 

HAVE MADE POSSIBLE MY EDUCATION 

THIS BOOK IS AFFECTIONATELY DEDICATED 



ACKNOWLEDGMENT 



The writer wishes to thank all those who have so 
kindly aided him in the preparation of this book. 

He is especially grateful for the valued comments 
and criticisms offered by the members of the Staff of 
the Department of Chemical Engineering, Carnegie 
Institute of Technology; for the facts which form the 
basis of Chapter X, by Dr. Samuel Haythorn of the 
Singer Memorial Laboratory, Allegheny General Hos- 
pital; and for data on TNT manufacture by Mr. 
Robert M. Crawford of the Grasselli Powder Co. 

The Chemical and Industrial Journals have been 
consulted freely, and much valuable material has been 
extracted therefrom. 

Department of Chemical Engineering, 
Carnegie Institute of Technology, 
Pittsburgh, Pa., May, 1918. 



TABLE OF CONTENTS 



CHAPTER I 

PAGE 

Introduction 1 

CHAPTER II 
Historical 6 

CHAPTER III 

The Theory of the Nitration of Toluene 20 

CHAPTER IV 
The Manufacture of TNT ' 29 

CHAPTER V 
The Purification of TNT 52 

CHAPTER VI 

Inspection and Testing of TNT 61 

CHAPTER VII 

Properties of the Trinitrotoluenes 77 

CHAPTER VIII 

Properties of the Mono- and Dinitrotoluenes 95 

CHAPTER IX 
Accidents in TNT Plants 106 

CHAPTER X 

TNT Diseases 112 

vii 



TRINITROTOLUENE 



CHAPTER I 
INTRODUCTION 

The almost universal adoption of trinitrotoluene 
as the most efficient explosive in modern warfare; the 
development and refinement of its manufacture, 
and the interesting chemistry of its compounds, as 
well as those of the lower nitro-derivatives of toluene 
has prompted quite extensive research as to their 
composition, structure, manufacture, properties and 
uses. The fact that the results of these researches 
have been varied; often quite contradictory; some- 
what disconnected and expressed with some confusion 
of terms would seem to warrant the publication of this 
little volume in which an attempt is made to gather 
together and correlate all accessible information on 
the subject, both theoretical and practical. 

Since the chemical name " trinitrotoluene " is 
rather^mysterious to the non-scientific mind, and since 
it is also much too lengthy for general use in this age 
of efficiency, concentration and hustle, there have been 
coined many abbreviations and substitutions of the 
word. In general these terms are local only, but, by 



2 TRINITROTOLUENE 

use in specifications, etc., they have: spread beyond the 
territory in which they originated. Little wonder is 
caused, therefore, that the uninitiated should confuse 
the several names now in vogue for trinitrotoluene, 
and that he should think " TNT " to be one substance, 
" trotyl " to be another, and so on. The entire list 
of contractions and designations is much too lengthy 
to give in its entirety, but the more familiar ones are 
these : 

"TNT"; the American contraction, and the one 
usually used for trinitrotoluene in this country. 

"Trotyl"; this term is of English origin, and is 
used almost exclusively in English specifications and 
literature. 

" Tolite "; the French abbreviation. 

"Trilite"; Spanish. 

" Fullpulver-02 " or simply " Fp-02 " is used by 
the Germans to denote trinitrotoluene. This is, of 
course, neither a contraction nor an abbreviation of 
the name itself, but denotes merely a certain explosive 
in accordance with the German system of classifica- 
tion. 

Some other terms are " Trinol," " tritol," " tri- 
tolo " and " coal tar salt," this last being the newest 
designation for trinitrotoluene. By comparing the 
above terms with the full word, the relation of most 
of them is easily seen. 

Trinitrotoluene is just what its name implies — a 
triple nitrated toluene. Toluene, itself, is a liquid 
prepared usually from coal tar, by distillation: This 
is the main source of this substance in North America, 
although it is prepared in smaller amounts from arti- 
ficial gas, the cracking of crude petroleum, etc. 




INTRODUCTION 3 

By treating toluene with nitric acid, three nitre- 
groups attach themselves to the molecule in this 
manner: 

CH 3 

O2N/NNO2 

+3H 2 0. 

N0 2 

This particular trinitrotoluene is one of the six 
isomeric compounds of that name, and is the one 
formed by the commercial nitration of toluene. Chem- 
ically it is the a, 1-2-4-6, or " symmetrical " tri- 
nitrotoluene. 

Trinitrotoluene belongs to the shattering class of 
explosives known as the " brisants." The members 
of this class possess great force, and upon exploding, 
shatter the containing shell into small pieces, thus 
doing more damage per shell. 

The other well-known member of the brisant class 
of explosives is picric acid, or trinitrophenol. Pre- 
vious to the use of trinitrotoluene, picric acid was used 
largely as the explosive charge in shells. There are 
several disadvantages in picric acid, however, which 
trinitrotoluene does not have. Picric acid forms salts 
(picrates) with a great number of the metals. These 
picrates are very unstable, and are quite sensitive to 
shock, thus giving rise to premature explosions which 
often result fatally. Trinitrotoluene is very inactive 
toward the greater number of the metals. Further- 
more, picric acid has a high melting-point (122.5°) 
while the melting-point of trinitrotoluene is low enough 
(80.6°) that it may be poured into the shell in the 
molten state without danger from fire. 



TRINITROTOLUENE 



On the other hand, trinitrotoluene is not quite as 
powerful as picric acid, but its insensibility to shock, 
together with the advantages cited above, have resulted 
in its almost totally replacing the latter in warfare. 
The first nation to use trinitrotoluene in shells was the 
Germans, who adopted it in 1904. 

The great insensibility of trinitrotoluene as com- 
pared to that of picric acid, is shown in the following 
table of minimum charges necessary for the detona- 
tion of both explosives : 



Detonator. 


TNT. 


Picric Acid. 


Mercury fulminate 


Gram. 
.36 
.11 
.095 
.145 
.09 
.07 
.04 


Gram. 
.30 


Cadmium fulminate 


.05 


Silver fulminate 


.05 


Mercurous azide 


.075 


Lead azide 


.025 


Silver azide 


.035 


Cadmium azide 


.02 







Aside from its use individually as an explosive, 
trinitrotoluene is often mixed with other ingredients. 
The most important of these blends, together with 
their analyses, are : 

" Thunderite "; TNT, 4 per cent; ammonium 
nitrate, 92 per cent ; flour, 4 per cent. 

"Permonite"; TNT, 10 per cent; ammonium 
nitrate, 42.5 per cent; potassium chlorate, 32.5 per 
cent; starch, 12 per cent; wood meal, 3 per cent. 

"Aluminium explosive"; TNT, 31 per cent; 
ammonium nitrate, 44.9 per cent; aluminium wool, 
24.1 per cent. 

"Plasteryl"; TNT, 99.5 per cent; resin, 0.5 per 
cent. 



INTRODUCTION 5 

"Macarite"; TNT, 30 per cent; lead nitrate, 70 
per cent. 

"Donarite"; TNT, 12 per cent; col.cot. 0.2 per 
cent; ammonium nitrate, 80 per cent; flour, 4 per 
cent; nitroglycerine, 3.8 per cent. 

Dinitrotoluene is also used in conjunction with 
other materials as an explosive. One such mixture is 
" Cheddite-02." The analysis of the mixture is: 

DNT, 15 per cent;- potassium chlorate, 79 per cent; 
mononitronaphthalene, 1 per cent; castor oil, 5 per 
cent. 

One further mixture deserves mention because of 
the use of DNT and TNT in the mixture. This 
explosive is called " triplastite." The analysis is: 

Mixture of DNT and TNT, 70 per cent; col.cot., 
1.2 per cent; lead nitrate, 28.8 per cent. 



CHAPTER II 
HISTORICAL 

Some doubt exists as to whom the honor of the dis- 
covery of toluene is due. Dr. W. Wilson in an article 
dated 1850, (1) gives the credit of the discovery to 
Deville, a French chemist, who obtained from balsam 
of tolu a compound to which he ascribed the name 
" benzoen." From the above article, Deville evi- 
dently did not analyze the " benzoen " but arbitrarily 
assigned to it the formula C14H16. 

Beilstein and Kuhlberg, in their " Eleventh Trea- 
tise on Isomers of the Toluene Series," (2) give the 
honor to Pelletier and Walters, also French chemists, 
who obtained an oil from the distillation of pine resin, 
and from which oil they separated a liquid which they 
called " retinaptha." Their description of this liquid 
is this: " It is a very clear liquid, . . . boiling at 108° 
C, and it is not completely solidified at —20°. The 
results of three analyses indicate the formula C7H8." 
(This is just half the molecular formula given by 
Deville to his substance.) " One could also give the 
formula C14H16, but there is no definite ground for 
such a statement. In fact, the vapor density is 3.23 — 
the vapor density corresponding to the formula C7H8 
would be 3.226." 

From this statement it would seem that Pelletier 
and Walters were already aware that a substance of the 

6 



HISTORICAL 7 

formula (supposedly) C14H16 had been isolated, and 
that, by determining the vapor density, they had proved 
it to be just half this molecular weight, or C7H8. On 
the other hand, there is no reason why — if they did 
know of the previous discovery of this same substance 
— they should give it a new name. The dates on 
which the above-mentioned men published their article 
seems to point to Pelletier and Walters as the dis- 
coverers — their work was completed about 1838, 
while Deville's work was published somewhere about 
1841. Of course, there is the possibility that Deville 
completed his work some years before his results were 
published. 

In 1843, Berzelius technically accorded the discovery 
of toluene to Deville by suggesting the name " toluol " 
or " toluene " for the compound, (3) the name being 
derived from " oil of tolu." 

Some of the scientists of that period (probably 
friends of Pelletier and Walters), did not approve of 
Berzelius' choice of name for this substance, and 
two of these, Muspratt and Hoffman, in a research 
paper dated 1845, take occasion to remark: (4) " Ber- 
zelius has proposed for this compound the name ' tol- 
uol ' or ' toluene,' names which are not very well 
chosen, but which we shall retain in the following dis- 
cussion." 

The " retinaptha " of Pelletier and Walters and the 
" benzoen " of Deville were proved to be the same sub- 
stance by the preparation of the nitro-derivatives, and 
by comparing the constants of those, and possibly the 
acid nitro-derivatives and corresponding toluidins. 

Glenard and Boudalt, at about the same time, prob- 
ably later than both Deville's and Pelletier and Wal- 



8 TRINITROTOLUENE 

ter's work, isolated toluene from " Dragon's blood." (5) 
No further reference, and consequently no identifica- 
tion of this substance, could be found. Glenard and 
Boudalt gave the name " dracyl " to the substance they 
isolated. Following the methods of their predecessors 
they proved the identity of dracyl and toluene. 

Still another man, Cahours, during the years 1847- 
48 isolated a substance from crude wood alcohol by 
treating the alcohol with sulphuric acid. He called 
this substance " toluen," which is so near " toluene " 
that naturally it would be supposed to be the same. 
Cahours demonstrated, however, that the formula of 
" toluen " was C14H8, which gives rise to a doubt as 
to whether his product was really identical with tol- 
uene. An abstract, dated 1849, reads thus: (6) 
" Cahours has separated from crude wood alcohol 
different oily hydrocarbons, some already known; 
some new. Toluen C14H8 is identical with the toluene 
of Deville. It distills between 108 and 112° C. 
Cahours found the vapor density to be 3.27. Through 
treatment with nitric acid he obtained mono- and 
dinitrotoluene, and from these, by reduction with 
ammonium sulphide, the corresponding toluidin and 
nitrotoluidin." 

It is rather difficult to understand why Cahours 
insisted on the formula C14H8 after having determined 
a vapor density of 3.27, which so closely checked 
Pelletier and Walter's determination. 

About 1850, Mansfield, an English chemist, iso- 
lated toluene from coal tar. (7) This discovery of 
Mansfield's practically ends the historical interest 
in toluene, since it has come to be the principal source 
of this substance. One further method of obtaining 



HISTORICAL 9 

toluene will be cited, however, because of its scientific 
interest. In 1846, two German chemists, Tollens and 
Fittig, prepared toluene synthetically from methyl 
iodide and brombenzene. (8) This method was a 
modification of Wurz' synthesis of the aliphatic hydro- 
carbons, and it is interesting because the primary prod- 
uct of the now commercially valuable " Fittig's syn- 
thesis " was toluene, the basis of the greatest explosive 
of modern times. 

The earliest reference to be found concerning the 
purification of coal tar toluene is contained in Wilson's 
paper, (9) wherein he states: "The best method of 
obtaining pure toluene consists in collecting the part 
which passes over between 100 and 120° C. and treat- 
ing this with one-half its weight of concentrated sul- 
phuric acid. I have not determined which substances 
are removed in this process ; the fact remains, however, 
that a constant boiling-point is obtained more easily 
through the use of sulphuric acid than without. The 
boiling-point of pure toluene was found to be 110° C. 
. . . Under all conditions a series of protracted dis- 
tillations is necessary to obtain this object." 

As is seen from this statement, Wilson followed the 
same method of procedure as is followed to-day in 
order to effect the removal of the olefines from the 
crude toluene. Modern plants, equipped with the 
latest type of fractionating stills, with their compli- 
cated columns, refluxes and fractional condensers are 
fortunately not put to the same trouble in the puri- 
fication of toluene as was Wilson. 

The history of the discovery and preparation of 
mononitrotoluene runs parallel with that of toluene, 
since it was by the preparation of the former that tol- 



10 TRINITROTOLUENE 

uene was identified by the several chemists. Deville 
prepared the mononitrotoluene and also the sulphonate 
of toluene. The nitro-compound he called " protoni- 
trobenzoen," and describes it in this manner: " It 
tastes like bitter almonds; smells suffocating at first 
then penetrating. Its specific gravity is 1.18 at 16°. 
It boils at 225°." The same chemist found the vapor 
density to be 4.95. The vapor density as calculated 
by him would be 7.87, basing the calculation on his 
formula of C14H16 for toluene. (10) 

Berzelius, in a research paper published in 1843, 
gives in detail the preparation of nitrotoluene. (11) 
The results of a series of researches to prove its con- 
stitution are mentioned also. Berzelius was misled 
by his results, as was Deville. His final conclusion 
states, " Nitrotoluene can be considered as a nitride 
of toluid oxide, Ci4Hi40=N." The chemical proper- 
ties of nitrotoluene were studied at length by Berzelius, 
but he evidently arrived at no definite conclusion re- 
garding these properties. 

Dr. Wilson, in the same article to which reference 
is made above, makes this statement concerning nitro- 
toluene: " The changing of toluene to nitrotoluene is 
carried out without difficulty in the usual manner. 
The boiling-point of nitrotoluene lies between 220 
and 225° C. This body boils without decomposition." 
The last statement of Dr. Wilson, concerning the ability 
of nitrotoluene to be distilled without decomposition, 
confirmed experiments carried out by Glenard and 
Boudalt. This question was a much mooted one at 
this time, since other chemists had proved to their 
entire satisfaction that nitrotoluene could not be dis- 
tilled without undergoing decomposition. Comment- 



HISTORICAL 11 

ing on this question, Beilstein and Kuhlberg (12) 
explain the decomposition of nitrotoluene as being due 
to the probable content of higher nitro-derivatives of 
toluene. This we now know to be the truth, and the 
firms who are purifying their nitrotoluene by distilla- 
tion are very careful to remove all the higher nitro- 
; compounds before attempting the distillation. 

About this time, another chemist entered the field 
of the nitro-compounds. This man was Jaworsky. 
He started out his work by preparing nitrotoluene, 
which he claimed to be a solid, and not a liquid as 
Deville, Wilson, and others had thought it to be. (13) 
Jaworsky represents about the best type of pure indus- 
trial chemist to be found in this period of time. His 
work on nitrotoluene had a great effect on the indus- 
tries; so much so, that at the Paris Exposition of 1867 
there was exhibited a great quantity of beautifully 
crystallized nitrotoluene. Whether this consisted of 
the pure solid isomer of nitrotoluene or whether it 
was a mixture of one or more nitrotoluenes and dini- 
trotoluenes, is not known. Jaworsky was also the 
first to produce toluidin — the homologue of aniline — 
by the reduction of nitrotoluene with tin and hydro- 
chloric acid. The immediate industrial result of 
Jaworsky's work was that the use of nitrotoluene as a 
dyestuff base was firmly established. 

Kekule, the great chemist whose " benzene ring " 
theory is now the basic law of the chemistry of the aro- 
matic compounds, worked exhaustively with nitro- 
toluene, and did much to clear the cloud caused by 
Jaworsky's contradiction of Deville's work. Kekule's 
work showed — to quote his words—" At least it is quite 
probable that the substance hitherto regarded as nitro- 



12 TRINITROTOLUENE 

toluene is nothing else than a mixture of nitrotoluene 
and nitrobenzene." 

Summarizing the work of these earlier investiga- 
tors of the nitrotoluenes, there is one fact that stands 
out very clearly throughout all their work — they had 
no thought of the possible isomerism of nitrotoluene. 
The results obtained by all the various work done by 
these chemists was finally interpreted by Kekule as 
meaning that nitrotoluene was a solid, and that the 
liquid obtained by Deville and others was a liquid 
only because of the admixture of nitrobenzene. 

This cloud began to disappear with the work of 
Rosenstill, who was the first to suggest the possibility 
of the existence of nitrotoluene in different forms. 
His work was later supplemented by Beilstein and 
Kuhlberg, who found in Rosenstill' s work the hint 
that led to their isolation of the three isomeric nitro- 
toluenes, and the classification and naming of these 
compounds. The results of Beilstein and Kuhl- 
berg's work was published in 1879, when, for the first 
time, the true constitutions of the nitrotoluenes was 
established. 

It is very peculiar, indeed, that most of the bril- 
liant earlier chemists, whose work did so much to lay 
the foundation of the present wonderful science, 
wound up their work with a probable error. The 
word " probable " is used intentionally, because in that 
formative period of the chemistry of the aromatics, 
with the constantly arising theories and hypotheses, 
there may appear errors which are in reality not such, 
but which were facts when viewed in the light of the 
then accepted laws. Future discoveries have changed 
many of these early ideas, and possibly it may be better 



HISTORICAL 13 

to state that they were led astray by statements and 
hypotheses which later proved to be without founda- 
tion. The particular point to which I refer is the 
nomenclature used by Beilstein and Kuhlberg for the 
nitrotoluenes. This may appear a small matter, but 
when reference is made to the publications of these men, 
and when these references are viewed in the light of 
present day accepted facts, their nomenclature is con- 
fusing. More so, because they made use of the terms 
" ortho," " meta," and " para," which are the same as 
are used to-day. The meta and ortho isomeric nitro- 
toluenes appear to be just reversed from those isomers 
now regarded as meta and ortho. This view was not 
due to Beilstein and Kuhlberg alone, for at least one 
other scientist, V. von Richter, was of the same mind. 
Von Richter states thus: (14) " Trinitrotoluene from 
meta mononitrotoluene crystallizes in yellow needles 
which melt at 82°." Now, the meta mononitrotoluene, 
according to modern orientation, will have the nitro- 
group in position three. (Throughout this book the 
methyl group in toluene will be considered as occupy- 
ing position one.) The trinitrotoluene that has a melt- 
ing-point of 82° (probably slightly incorrect), is the 
symmetrical trinitrotoluene, with the nitro-groups in 
positions 2-4-6. It would therefore be impossible for 
this symmetrical trinitrotoluene to result from what 
von Richter and Beilstein call meta nitrotoluene, unless 
one nitro-group actually shifts its position in the mole- 
cule which, as is known, is impossible with the con- 
ditions existing as they do in the process of nitration. 
Returning, now, to Beilstein and Kuhlberg, and 
their " Eleventh Treatise," there is found a detailed 
summary of the constants of three nitrotoluenes: 



14 



TRINITROTOLUENE 





Melting-point. 


Boiling-point. 


Ortho 

Meta 


16 


230-231 
222-223 


Para 


54 


235-236 



These same constants of the nitrotoluenes named 
as we have them to-day, are different: 





Melting-point. 


Boiling-point. 


Ortho 


-10.5 
16 
54 


218-220 


Meta 

Para 


230 
234 







By comparing the above summaries, it is seen that 
the ortho compound of the earlier chemists is identical 
with the present meta nitrotoluene, and vice versa. 
That the early view was incorrect may be further 
proved by investigating the properies of the meta 
compounds. In all reactions the meta compounds react 
differently from the ortho and para compounds. For 
instance, in the nitration of toluene, the ortho and para 
nitrotoluenes are formed in large amounts, and the 
meta in small amounts. Further, when the mono- 
nitrotoluenes are nitrated to dinitrotoluene, the ortho 
and para mononitrotoluenes are very easily nitrated 
further, and the meta difficultly so. In other words, 
the ortho and para compounds form one part of the 
class, while the meta stands alone as the other part. 
With the early nomenclature, the meta and para would 
be placed together, while the ortho would stand alone. 
If, now, this view of the matter is accepted, Von Rich- 
ter's statement becomes entirely correct. 



HISTORICAL 15 

After Beilstein and Kuhlberg completed their work 
on the nitrotoluenes, they set about investigating tol- 
uene to discover whether or not this substance existed in 
isomeric forms, thinking thereby to explain the isom- 
erism of the toluene derivatives. Their experiments 
are interesting in the extreme, but are too lengthy to 
discuss in this book. Suffice it to say that the results 
of their research proved conclusively that toluene 
existed in but one form. 

In considering the discovery of dinitrotoluene, we 
must again give the credit to Deville. His original 
paper on the general subject of toluene and its nitra- 
tion derivatives contains the statement that he pre- 
pared the dinitro-compound, which he called " binitro- 
benzoen," in direct accordance with the scheme of 
nomenclature he adopted. Deville gives the melting- 
point of his preparation as 71°. Therefore it is inferred 
that his " binitrobenzoen " was 1-2-4 dinitrotoluene. 
(15) 

Cahours also prepared a dinitrotoluene, but unfor- 
tunately he did not leave any data as to which of the 
isomers he obtained. 

Beilstein and Kuhlberg prepared two dinitrotol- 
uenes, but give the melting-point of but one of the two. 
This was the same as that of Deville. The work of 
Beilstein and Kuhlberg seems to have been mostly 
on the mononitro-compounds of toluene, and the acidic 
and basic compounds of mononitrotoluene. 

Dr. O. Cunerth, in a paper dated 1874, (16) gives 
probably the most comprehensive summary of the his- 
tory and discovery of the dinitrotoluenes to be found. 
His paper begins with this statement: " It is known 
that in the nitration of toluene, two modifications are 



16 TRINITROTOLUENE 

obtained; the ortho and para." This statement is 
further proof that Beilstein was mistaken in his no- 
menclature. 

The second dinitrotoluene was discovered by Rosen- 
still, but he was not sure whether it was the 1-2-3, 
the 1-2-5, or the 1-2-6 compound. Dr. Cunerth, 
after much work, identified this dinitrotoluene as the 
1-2-6 modification. 

The 1-3-4 dinitrotoluene was discovered by Beil- 
stein, who did this work independently of Kuhlberg 
in 1873. It was then that Beilstein gave the names to 
the three known dinitrotoluenes. The 1-2-4 modi- 
fication he called the a) the 1-2-6, the /3; and the 
1-3-4, the 7. This nomenclature is not strictly 
adhered to, by modern chemists, the usual manner of 
denoting a certain di- or trinitrotoluene being to state 
the position occupied by the groups. 

Lampricht is credited with the isolation of the next 
dinitrotoluene. This was the 1-2-5 derivative, and 
was discovered by Lampricht during experiments on 
the action of fuming nitric acid on toluene. 

The isolation of the remaining two modifications, 
the 1-2-3 and the 1-3-5 is somewhat in doubt. The 
sources of information at hand point to either Nolting 
and Witte or to Bernthsen as the discoverers. 

In considering the history of the trinitrotoluenes, it 
is found that modern chemists enter the field. The first 
three of these modifications were discovered quite early, 
it is true, but the last three were discovered within the 
past three years, and their discovery was due indirectly 
to the great war. With the trinitrotoluenes, as with 
the dinitro-, there are possible six isomers. The most 
interesting of the six is the 1-2-4-6 or symmetrical 



HISTORICAL 



17 



modification. Peculiarly enough, this was the first 
discovered, very likely because it is the modification 
present in the largest proportions in the nitration of 
toluene. 

The discoverer of the symmetrical trinitrotoluene 
was Dr. J. Wilbrand, who, at the time of his discovery, 
was working at Gottingen University. Dr. Wil- 
brand's discovery was made in 1862 or 1863. Speaking 
of his research, which led to the isolation of the sym- 
metrical TNT, Dr. Wilbrand says: " The preparation 
of trinitrotoluene is very easy. Toluene is heated to 
about boiling temperature with a mixture of fuming 
nitric and sulphuric acids for a day. The acid mix- 
ture is agitated with water, and the residue is crystal- 
lized after washing with water and drying with alcohol. 
The analysis of trinitrotoluene is: 




Trinitrotoluene crystallizes in white glistening 
needles, which are, to all appearances, scarcely differ- 
ent from dinitrotoluene. This substance melts at 
82° and is easily soluble in hot alcohol, but very slightly 
in cold. In ether it is easily soluble. Boiling alkalies 
react much easier with trinitrotoluene than with dini- 
trotoluene. From the deep red alkaline solution, 
acids precipitate dark flocks." (17) 

The constitution and formula of trinitrotoluene was 
established by Claus and Becker, who, by experiment, 



18 



TRINITROTOLUENE 



proved it to be symmetrical. (18) The melting-point 
was found to be 82°, in accordance with Dr. Wilbrand's 
statement. In the light of modern research, this melt- 
ing-point appears too high. The correct melting-point 
is probably 80.6°. 

The next trinitrotoluene to be isolated was the 
1-2-3-6 modification. This was discovered by Paul 
Hepp in 1882. (19) Hepp found the melting-point 
of this trinitrotoluene to be 112°. 

The discovery of the 1-2-3-6 compound was fol- 
lowed very shortly by the discovery of the 1-2-4-5 
modification by Beilstein, who isolated both the 1-2-3-6 
and the 1-2-4-5 isomers the same year that Hepp 
isolated the 1-2-3-6. Beilstein found the melting- 
point of the 1-2-4-5 isomer to be 104° C. 

The remaining three trinitrotoluenes have been 
discovered in very recent times. In 1914, Giua and 
Molinari discovered the 1-2-3-5 modification. (20) 
The isolation of this compound was accomplished while 
the discoverers were working on an industrial problem 
with the oily substance resulting from the centrifugali- 
zation of crude dinitrotoluene. It will be remembered 
that Nolting and Witte worked with this same sub- 
stance in 1885. These latter investigators overlooked 
this trinitrotoluene and also several dinitrotoluenes, 
since Giua and Molinari found the following constitu- 
ents in the oil. 



Mono-. 


Di-. 


Trinitrotoluenes. 


1-3 
1-4 


1-2-4 
1-2-5 
1-2-6 
1-3-4 


1-2-4-6 
1-2-3-5 



HISTORICAL 19 

Giua and Molinari give the melting-point of this 
trinitrotoluene as 79.5°. 

The next trinitrotoluene to be isolated was the 
1-3-4-5 modification. This was discovered by Korner 
and Contardi in 1915. (21) Under what conditions, 
or from what source this trinitrotoluene was dis- 
covered is not known, since the original reference is 
not at hand. The melting-point given by the dis- 
coverers is 97.2°. 

The last trinitrotoluene, and the last of the fifteen 
possible nucleus-substituted nitro-derivatives of toluene, 
is supposed to have been discovered by Coparisow 
during the latter part of the year 1915. (22) The 
melting-point of this trinitrotoluene is 137.5°. 

The history of the nitro-derivatives of toluene is a 
long one. There is interest at each step, however, 
because of the periods of time involved, and because 
of the great chemists who were concerned in the isola- 
tion and constitution of these compounds. The mono- 
nitrotoluenes formed the working subjects for the work- 
ing out and proof of a considerable number of the basic 
laws of orientation ; a fact which is in itself of no little 
interest. 



CHAPTER III 
THE THEORETICAL NITRATION OF TOLUENE 

In this discussion of the theoretical nitration of 
toluene, I shall make use of the ideal process — the three- 
stage. If either the one- or two-stage processes were 
substituted, there would be changes in minor points 
only, and I think the three-stage illustration will ren- 
der the theory more clear. 

The reactions of the first nitration of toluene are as 
follows : 

First stage: 

C 6 H 5 CH 3 +HNO3 -* C 6 H 4 (CH 3 ) (N0 2 ) +H 2 0. 

There is also a possibility that the reaction may go 
forward in two steps, the first step being the sulpho- 
nation of the toluene, and the second step the substitu- 
tion of nitro-groups for the sulphonic groups: 

C 6 H 5 CH 3 +H2SO4 -> C 6 H4(CH 3 )(S03H) +H 2 

and, 

C 6 H4(CH 3 )(S0 3 )+HHN0 3 ^C 6 H4(CH 3 )(N0 2 )+H 2 S04. 

The reactions of the second stage consist first in 
sulphonating the mononitrotoluene, and then in nitrat- 
ing the sulphonate: 

20 



THE THEORETICAL NITRATION OF TOLUENE 21 

C6H 4 (CH3)(N0 2 )+H 2 S04 

-> C6H3(CH 3 )(N0 2 )(S0 3 H) +H 2 0, 
and 

CeHaCCHsXNOaXSOsH) +HNO3 

-» C 6 H 3 (CH 3 )(N0 2 ) 2 +H 2 S04. 

The third-stage reaction is similar to the second 
stage : 

C 6 H3(CH3)(N0 2 )2+H 2 S04 

-> C 6 H 2 (CH3)(N0 2 ) 2 (S03H) +H 2 0, 
and 

C 6 H 2 (CH 3 )(N0 2 ) 2 (S03H) +HNO3 

^C 6 H 2 (CH3)(N0 2 )3+H 2 S04. 

In each stage there may be the reactions of either 
previous or later stages taking place, because of the 
impossibility of absolute control. 

The theory that sulphonation takes place before the 
nitration can be accomplished may be the key to the 
question as to why some mono- and dinitrotoluenes 
are easily nitrated, and some are difficultly nitrated. 
The sulphonic group follows the laws of orientation 
perhaps more closely than almost any other group, 
and this explains why (assuming the sulphonation 
theory) dilute nitric acid will not nitrate direct, but 
will merely replace a sulphonic group. Therefore, if 
the sulphonic group is not already in place, the nitro- 
group cannot enter the molecule. So, if the previous 



22 TRINITROTOLUENE 

stage has resulted in the formation of isomers with the 
groups in such positions that the sulphonic group cannot 
enter the molecule easily, the isomer will be nitrated 
only by very strong nitric acid, or by using some special 
method of introducing the sulphonic group. 

This solution to the question would seem to indicate 
that in the first-stage nitration the sulphonation does 
not take place, but that the toluene is nitrated directly 
by the use of nitric acid. 

Starting with toluene, purified as is considered neces- 
sary for nitrations, the primary nitration is to mono- 
nitrotoluene. The theoretically perfect nitration would 
proceed in this manner: 



CH 3 CH 3 CH 3 CH 3 



Nro 2 /\no 2 2 on/ 



N0 2 



\/ \/ \/ 

N0 2 N0 2 

This nitration, however, is never accomplished, for the 
mononitrotoluene consists of all three isomeric forms. 
The mononitrotoluene modifications are present in 
the proportion of 38 per cent para, 60 per cent ortho, and 
2 to 4 per cent meta. (1) This result is exactly what 
would be expected, because with the methyl group in 
position 1, the tendency of the nitro-groups is to enter 
either position 2 or position 4. This fact holds true 
even with the more generally accepted view that the 
first stage of the reaction consists in sulphonating the 
toluene, because the sulphonic group behaves and 
orientates just the same as the nitro-group, and with 
the methyl group in position 1, the sulphonic group 
will also enter either position 2 or position 4. The 



THE THEORETICAL NITRATION OF TOLUENE 23 

nitro-group can then easily replace the sulphonic 
group. 

The formation of the small amount of meta nitro- 
toluene is explained thus by Holleman: (2) " It is 
apparent that there is an opposition between the ortho 
and para derivatives on one hand, and the meta deriv- 
atives on the other. Either tjie first two are the chief 
products, or the last. Concerning the temperature 
of the reaction, it has been proved that the quantity 
of the by-products is the smaller, the lower the tem- 
perature of nitration." This statement of Holleman 
is based on earlier work by himself, and in a paper he 
gives this tabulation : (3) 

CONSTITUTION OF MIXTURE OF UNITS 



Temp, of Nitration. 


Ortho. 


Meta. 


Para. 


Deg. C. 


PerCent. 


Per Cent. 


PerCent. 


-30 


55.6 


2.7 


41.7 





56.0 


3.1 


40.9 


30 


56.9 


3.2 


39.9 


60 


57.5 


4.0 


38.9 



Considering, then, the mixture of mononitrotoluenes 
to consist of, approximately, 38 per cent para, 4 per 
cent meta, and 58 per cent ortho nitrotoluene; the 
reactions which occur od nitrating to dinitrotoluene 
will be investigated. 

This nitration takes both the ortho and para nitro- 
toluenes largely to but one dinitrotoluene — the 1-2-4 
modification — but a small amount of 1-2-6 is formed. 
The nitro-group here, as before, conscientiously follows 
the law of orientation and enters a position meta to 



24 TRINITROTOLUENE 

another nitro-group, but still ortho or para to the methyl 
group. Of course, as in the first-stage nitration, a 
small amount of the mononitrotoluene (especially 
the meta) may, under the influence of conditions con- 
cerning which we know nothing, attach nitro-groups 
in other than the specified positions. 

By the nitration of meta nitrotoluene there is formed 
mainly the 1-3-4 dinitrotoluene. Some small amounts 
of 1-2-3 and 1-3-6 (or 1-2-5) isomers also result from 
this nitration. (4) In each of these cases it may be 
noticed that the tendency of the nitro-group is to 
resist the intruding prime nitro-group, which has 
entered the molecule contrary to the laws governing 
its action, because the second group will enter either 
ortho or para to the methyl group. These isomeric 
dinitrotoluenes, other than the 1-2-4, and the tri- 
nitrotoluenes together with some unchanged mono- 
nitrotoluene constitute the oil that separates from the 
1-2-4 dinitrotoluene by centrifugalizing or cooling 
and filtering. This oil is known in Germany as " Bini- 
trotropfol." Nolting and Witte (5) state that this 
oil constitutes about 7 per cent of the entire charge. 
Various chemists have analyzed the oil, their analyses 
being summarized and checked by Nolting and Witte, 
who found, in addition to the substances isolated by 
the others, some meta nitrotoluene. According to 
Nolting and Witte, the analysis of this oil shows the 
presence of 1-2-4 and 1-2-6 dinitrotoluenes, and 
1-3 and 1-2 mononitrotoluenes. Giua and Molinari 
(6) discovered some trinitrotoluenes in the oil which 
were evidently overlooked by their predecessors. 

Summarizing the products of the second stage, the 
following nitro-derivatives may appear in the mix- 



THE THEORETICAL NITRATION OF TOLUENE 25 

ture. This summary assumes no separation of the 
binitrotropf ol : 



MNT. 


DNT. 


TNT. 


1-3 


1-2-4 


1-2-3-4 


1-2 


1-2-6 


1-2-4-6 


1-4 (possibly) 


1-2-3 


(1-3-4-5) 




1-3-4 


1-2-4-5 (1-3-4-6) 




1-2-5 (1-3-6) 


(all questionable) 



The amount of impurities; that is, products other 
than 1-2-4 dinitrotoluene, amounts to from 7 to 8 
per cent. 

I The third stage is much more complicated than 
either the first or the second, on account of having so 
many things with which to deal. Possibly by consider- 
ing the action of each compound separately, the result 
will be made more clear. 



MONONITROTOLUENES 

1-3 nitrates to 1-3-4 DNT (possibly further nitrates to 1-3-4-5 

TNT) (7); 
Also 1-2-3 DNT (possibly further nitrates to 1-2-3-4 TNT) (8); 
Also 1-2-5 DNT (possibly further nitrates to 1-2^-5 TNT) (8); 
1-2 nitrates to 1-2-6 DNT (9) \ (Both possibly further nitrated to 
also 1-2-4 DNT (10). J 1-2^-6 TNT). 



DINITROTOLUENES 



1-2-4 nitrates to 1-2-4-6 trinitrotoluene (10); 

1-2-6 " 1-2-4-6 " (9); 

1-2-5 " 1-2-4-5 " (8); 

1-3-4 " 1-2-3-1 " (also possibly 1-3-4-5) (7); 

1-2-3 " 1-2-3-4 if (8). 



26 



TRINITROTOLUENE 



(The German theory of nitration, advanced by Hepp, Escales, etc., 
and the Italian theory, which is supported by Giua, Molinari, Copari- 
sow, and others; differ at this point. The Germans assert that 1-3-4-5 
TNT is formed from 1-3-4 DNT, while the Italian theorists state that 
this is impossible. The statements given in substantiation of both 
theories are quoted at the end of this chapter.) 

The trinitrotoluenes remain unchanged upon 
attempts to further nitrate, unless too strong a nitrat- 
ing mixture is used. In this case thay may be oxidized 
to trinitrobenzoic acids or to tetranitromethane. (11) 

All of the lower products of nitration must, of neces- 
sity, be included in the products of the third-stage nitra- 
tion, because a small amount of any or all of these may 
have escaped nitration in all three stages. There is no 
reason to suppose that any one of the nitration reactions 
may have proceeded to completion, with the possible 
exception of the nitration of 1-4 mononitrotoluene. 
This particular nitrotoluene is the most easily nitrated 
of the entire number, and from all reports, is never found 
in the finished product. (12) 

Summarizing the products which may be found in 
the crude trinitrotoluene, the following formidable 
list appears: 



MNT. 


DNT. 


TNT. 


1-2 
1-3 


1-2-4 

1-2-6 

1-2-5 (1-3-6) 

1-3-4 

1-2-3 


1-2-4-6 

1-2-3-4 

1-2-4-6 (1-3-4-6) 

1-3-4-5 



Tabulating the above summary in the order of 
nitration, and in view of the two theories advanced 
for the nitration, the following tables result: 



THE THEORETICAL NITRATION OF TOLUENE 27 



GERMAN 



MNT. 


DNT. 


TNT. 


1-2 
1-3 
1-4 


/ 1-2-4 j 
\ 1-2-6 J 

f 1-3-4 

1 1-2-3 
I 1-2-5 
f 1-2-4 1 
I 1-2-6 1 


1-2-4-6 

f 1-2-3-4 

\ 1-3-4-5 

1-2-3-4 

1-2-4-5 

1-2-4-6 



ITALIAN 



MNT. 


DNT. 


TNT. 


1-2 


1 1-2-4 | 
I 1-2-6 / 


1-2-4-6 




f 1-3-4 


1-2-3-4 


1-3 


1-2-3 


1-2-3-4 




1 1-3-6 


1-3-4-5 


1-4 


1-2-4 


1-2-4-6 



The differences in these two schemes are self 
evident. The Italian theory is probably correct, in 
that much more is known about the behavior of the 
various nitrotoluenes on nitration than was known when 
the German theory was proposed. In defense of his 
theory, Hepp states as follows: 

" The theory is, that by nitration of meta nitro- 
toluene not less than five of the possible six trinitro- 
toluenes are formed. Beilstein and Kuhlberg hold 
that a trinitrotoluene is formed whose melting-point 
is 76 to 80°. They themselves doubt the constitu- 
tion of this compound. ' Possibly,' they conclude, 



28 TRINITROTOLUENE 

1 the small amount of substance we had was a mixture.' 
The truth is, we have succeeded in demonstrating that 
from a mixture of the nitration products of meta 
nitrotoluene at least two trinitrotoluenes may be 
isolated. . . . The first of these is a difficultly soluble 
compound having a melting-point of 104° C. The 
second, which I shall designate as the beta compound, 
is an isomer of the first, and melts at 112° C." (13) 

Giua's statement is much more brief and to the 
point. He says: 

" The direct nitration of toluene can give but three 
trinitrotoluenes, these are the 1-2-4-6, the 1-3-4-6, 
and the 1-2-3-4. Only through dinitrotoluidin can 
the other three be formed. (14) 



CHAPTER IV 
THE MANUFACTURE OF TNT 

The complete manufacture of trinitrotoluene in- 
volves the several processes of nitration, separation, 
washing, crystallization and possibly purification. 
The experimental stage has been passed in every one of 
these various divisions in the manufacture of this prod- 
uct, until the modern plant runs as smoothly as a well- 
oiled machine. The apparatus necessary to carry on 
any one or all of the steps in the manufacture of TNT 
is now well standardized, and many excellent machines 
are on the market for accomplishing the end toward 
which every manufacturer works — a pure product. 
A detailed description of the necessary apparatus will 
not be gone into, but a brief outline of the requirements 
to be fulfilled by the various machines will be given in 
their respective places. 

The first step in the manufacture of TNT is the 
the nitration. This reaction is carried out in a large 
vessel called the nitrator. This nitrator is generally 
a cylindrical kettle or tank, built of either an acid-proof 
cast metal or of boiler plate. The material of which 
the nitrator is built should be thoroughly tested with 
the acids of various concentrations met with in the 
manufacture of the product. The nitrator must be 
well equipped with cooling coils and heating coils so 
placed that the temperature of the reacting mixture 

29 



30 TRINITROTOLUENE 

responds instantly to the operation of these coils. The 
cooling is effected by the circulation of cold water 
through one set of coils, and the heating coils must be 
supplied with either superheated steam, or steam under 
pressure. Some attempts have been made to build a 
nitrating kettle with but one set of coils, this set serving 
for both heating and cooling. So far as I am aware, 
there has never been a really efficient nitrator yet 
built along the above line. The trouble with this 
type of machine is that when cold water is wanted, it 
is wanted quickly, and sufficient time to manipulate 
the several valves necessary on the above type of 
machine is not to be had. In addition to the tem- 
perature control coils, the nitrator must be equipped 
with a good agitating apparatus. This agitator is 
just as necessary as the water and steam coils, and, 
through keeping the mixture of toluene and acid uni- 
form, aids in maintaining the temperature level. The 
manufacture of TNT is essentially a problem in tem- 
perature control. After the nitration is complete, the 
rest of the process is easy. In order to check the opera- 
tor of the nitrating kettle it is well to install a recording 
thermometer in each unit. This eliminates error, and 
causes the operator to be more careful, because he 
knows that a mechanical watch is being kept on his 
work. 

I have noticed a tendency in quite a number of TNT 
plants to perform the nitration in a rather slip-shod 
manner, and on remarking concerning it this reply 
was made: " Well, its cheaper to use a little less acid 
in the nitration and purify the product afterwards." 
This policy is very bad, it is both expensive and non- 
efficient. It must be remembered that while TNT is 



THE MANUFACTURE OF TNT 31 

comparatively safe, it is made primarily to explode. 
Now, the more care taken with the manufacture of 
TNT — the less explosions in the plant, and the more 
explosions out of the plant. 

There are three general processes for the nitration 
of toluene to TNT. These are the one-stage, the two- 
stage, and the three-stage. All of these are being used 
at present in North America, but the three-stage seems 
to have the greatest preference. As the names imply, 
the process involves either one, two or three separate 
nitrations to carry the toluene to TNT. In some 
respects, the names " one-stage," " two-stage," etc., 
are misleading, because in every preparation of TNT, 
whether it be by the one-stage, the two-stage or the 
three-stage process, there are three distinct nitrations. 
With the one-stage process these three nitrations are 
all effected with the one acid mixture and without 
separation of the nitro-derivatives and the spent acid 
until the TNT is completed. Similarly, the two- 
stage and the three-stage processes accomplish the 
same thing in either two or three different steps, each 
step necessitating separation of the spent acid, and the 
addition of fresh acid. It must not be supposed, 
however, that the entire amount of the toluene is con- 
verted to mononitrotoluene before any of the mono- 
is nitrated to dinitrotoluene, or that all of the mono- 
Ditrotoluene is nitrated to dinitrotoluene before the 
di- is nitrated to TNT. This ideal result is not obtained 
with even the three-stage process. No matter which 
of the three processes is used, there will always be more 
or less impurities existing at each stage in the form of 
higher or lower nitration products. 

The toluene which is to be used as the raw material 



32 TRINITROTOLUENE 

in the manufacture of TNT must be very pure. The 
standard specifications now current in the United 
States are as follows : 

" The first drop must distill not below 108° C. 

" 95 per cent of the entire sample must distill with- 
in 2°. 

" The dry point must be below 112° C." 

In addition, the toluene must be practically free 
from olefines or members of the di-oleflne series. This 
demands that the toluene be washed several times with 
concentrated sulphuric acid to remove these com- 
pounds. The laboratory test for olefines consists in 
agitating some of the toluene with a certain percentage 
of concentrated sulphuric acid. If olefines are present, 
the acid layer will acquire a yellow to red color. This 
color must not be deeper than whatever shade the cer- 
tain plant has adopted as its standard. The com- 
parison standard colors consist of definite concentra- 
tions of solutions of potassium dichromate, chromic 
acid, etc. 

The presence of olefines is dangerous because these 
substances form nitro-compounds in the nitration proc- 
ess, and these compounds are rather unstable. A fire 
or even an explosion may possibly result if the toluene 
is not freed from them. The presence of members of 
the aliphatic or paraffin series is not nearly so detri- 
mental as the presence of the olefines. These com- 
pounds do not react on nitration, and with the three- 
stage process they may be removed after the nitra- 
tion to mononitrotoluene. 

As stated in Chapter III, the ideal nitration of 
toluene to TNT would be toluene to 1-2 nitrotoluene, 
to 1-2-4 dinitrotoluene, to 1-2-4-6 TNT. But this 



THE MANUFACTURE OF TNT 33 

is never accomplished. It is approached most nearly 
with the three-stage process, in which process puri- 
fication is possible at each step. In order to compare 
the three processes, an outline of each is given. 

Note. — The acid mixtures given are approximate only. Each plant 
has determined just which mixture will give the best results, some of 
these mixtures varying as much as 10 per cent. A statement of the 
exact analysis of the mixed acid is therefore impossible. 

The One-stage Process. In the one-stage process, 
but one acid mixture is used. This mixture consists 
of 75 per cent sulphuric acid, and 25 per cent nitric 
acid. The usual charge for this process is in the ratio 
of one part toluene to twelve parts mixed acid. Each 
kilogram of toluene requires, therefore, 3 kilograms 
nitric acid and 9 kilograms sulphuric acid. 

The toluene is added to the acid in the one-stage 
process. The termination of the inlet pipe is in a kind 
of well at the bottom of the nitrator, and the toluene is 
nitrated before it can separate and spread about. 
During the addition of the toluene the temperature 
must not rise above 30° C. This addition requires 
from two to two and one-half hours. After the addi- 
tion is complete, the temperature of the mixture is 
raised to 90 to 95° C, by means of the steam coils. 
This temperature is maintained for two hours, during 
which time the mononitrotoluene is nitrated to dinitro- 
toluene. The temperature is then further increased to 
120°, and is " cooked " for an additional two hours. 
The nitration is now considered finished, and the charge 
is ready for separation, washing, and graining. In 
many chemical plants a chemist tests the charge of 
TNT, and the time of the final cooking is determined 
by the solidification point of the mixed TNT and acid. 



34 TRINITROTOLUENE 

This principle of chemical control is adopted sometimes 
in the two- and three-stage processes as well as in the 
one-stage process. The yield of TNT by the one- 
stage process is 1.9 kilos per kilo toluene used. 

The Two-stage Process. There are two possible 
modifications of the two-stage process: 

1. Nitration from toluene toMNT; separation and 
purification of the mononitrotoluene, and nitration to 
TNT. 

2. Nitration to dinitrotoluene, separation of this 
product from the spent acid, and further nitration to 
TNT. 

The second modification has been practically dis- 
continued in this country, and will therefore not be 
discussed. 

The first stage of the other modification of the two- 
stage process requires a mixed acid which contains 
30 per cent nitric acid, 55 per cent sulphuric acid, 
and 15 per cent water. The proportions for the charge 
are one part toluene to two and one-half parts acid 
by weight. This process differs from the one stage 
in that the toluene is placed in the nitrating kettle and 
the mixed acid is added. The addition of the acid is 
carried out at a temperature not exceeding 40° C, 
and consumes one and one-half hours. The charge is 
then heated to 60° for one hour, and the mononitro- 
toluene is separated from the spent acid. At this point 
of the process various procedures are adopted. The 
mononitrotoluene may be washed and distilled, or it 
may be separated from the impurities present by 
solution. There has been much discussion as to 
whether or not mononitrotoluene can be safely dis- 
tilled. Recent investigations on the subject indicate 



THE MANUFACTURE OF TNT - 35 

that it can be safely distilled providing there is no 
trinitrotoluene present. In every case, however, the 
distillation should be made under reduced pressure, 
as this lessens the danger from explosions. 

Following the purification of the mononitrotoluene, 
or in case no purification has been made, following the 
separation from the spent acid, the mononitrotoluene 
is placed in the nitrator and is sulphonated with an 
amount of sulphuric acid equal to three times the weight 
of the mononitrotoluene. This requires about one-half 
hour. The reaction mixture is then heated to 70° and 
mixed acid containing 50 per cent each of nitric acid 
and sulphuric acid, equal in weight to the sulphuric 
acid used for sulphonating, is added through a period 
of one hour. After the addition is complete the charge 
is cooked at a temperature of 120° C. for two hours, 
then separated, washed, etc. 

The amount of acid necessary in the two-stage 
process per kilogram toluene is 5.6 kilos sulphuric, 
and 2.2 kilos nitric. The yield of TNT per kilo tol- 
uene is 1.99 kilos. 

A two-stage process has been proposed by Langen- 
scheidt similar to the one outlined above, the main 
difference being that the final cooking is done at 140° C. 
Humphrey has made an especial study of this process, 
and makes certain recommendations concerning its 
use. (1) He recommends Langenscheidt's process, but 
his investigations have shown that better yields of TNT 
are produced by operating at a somewhat lower tem- 
perature (120 to 125°) than 140° as prescribed by 
Langenscheidt, and maintaining the lower temperature 
for a longer time than that specified for the high tem- 
perature. The proportions of acids to toluene were 



36 TRINITROTOLUENE 

such that the water concentration in the final mixture 
was about 4.4 per cent. The experimental data indi- 
cate that the yield of TNT at a given temperature is 
not a function of the water concentration of the reac- 
tion mixture as assumed from 

C6H4CH3NO2+2HNO3 <=± C6H 2 CH3(N0 2 )3+2H 2 0. 

In his discussion Humphrey makes perfectly clear the 
point that the above statement does not apply to either 
very low or very high water concentrations, because 
experiments have shown that with a very high water 
concentration the nitro-group enters the side chain of 
the toluene molecule, while with a low water concen- 
tration, oxidation products, such as trinitrobenzoic 
acids, result. 

E. J. Hoffman, (2) has made a study of the effects 
caused by the addition of the toluene to the acid, and 
vice versa. In his experiments with the two-stage 
method (nitrating first to mononitrotoluene and then 
to TNT), he used an acid mixture of one part nitric 
acid (gravity 1.42) to two parts sulphuric acid (gravity 
1.84). When the toluene was added to the acids the 
yield was 60 per cent mononitrotoluene and 40 per 
cent dinitrotoluene. On the other hand, when the 
acids were added to the toluene very little dinitrotol- 
uene was formed. The temperature was more easily 
controlled in the first procedure, in which the toluene 
was added to the acid. Providing the nitration product 
is to be further nitrated to TNT, the presence of the 
dinitrotoluene is not objectionable. Hoffman's yield 
with this method was 75 per cent of TNT with a melt- 
ing-point of 78 to 80° C. 



THE MANUFACTURE OF TNT 37 

The Three-stage Process. The first-stage acid 
for this process is composed of 70 per cent sulphuric 
acid, 15 per cent nitric acid, and 15 per cent water. 
The acid is run into the toluene, the addition generally 
taking about two hours. The temperature during the 
addition of the acid must not rise above 30° C. The 
proportion of acid to toluene is three to one. Follow- 
ing the acid addition the temperature is raised to 60° C, 
and is held at this point one and one-half hours. The 
spent acid is then separated, and the mononitrotoluene 
is either purified and nitrated to dinitrotoluene, or the 
nitration is made without any purification other than 
the separation of the spent acid. 

The acid used in the second stage contains 60 per 
cent sulphuric, 25 per cent nitric, and 15 per cent water. 
The acid is added to the mononitrotoluene at 75° C, 
one and one-half hours being consumed in the opera- 
tion. After this addition has been made, the charge 
is cooked at a temperature of 90° for one and one-half 
hours. Then the spent acid is separated, and the dini- 
trotoluene is ready for centrifugalization, or nitration 
to TNT without purification. 

The first step in the third stage is the sulphonation 
of the dinitrotoluene. Oleum (fuming sulphuric acid) 
is used for this purpose in the majority of plants. The 
acid may be added very rapidly in the third stage, 
since the temperature is 90 to 100°. The acid analysis 
shows 50 per cent each sulphuric and nitric. When 
the addition is complete, the temperature is raised to 
120° and the charge is cooked for one and one-half 
hours. The nitration is then supposedly complete, 
and the TNT is separated from the acid, and is ready 
for washing. The yield of TNT per kilo toluene is 



38 TRINITROTOLUENE 

2.2. The total acid necessary is 2 kilos nitric and 
5 kilos sulphuric per kilo toluene. 

The German process of manufacturing TNT is of 
interest at this point, since the manufacture of this 
product originated in this country. The two-stage 
process is the one in greatest use in Germany, and in 
many plants the mononitrotoluene is separated, one 
of the isomers being used in the dye plants, while the 
other two are nitrated further to TNT. The first 
stage of the German process consists in placing 90 
liters of toluene in the nitrating kettle and adding 
an equal volume of nitric acid (gravity 1.25) at a tem- 
perature of 30° or lower. By using this acid alone, 
the Germans claim that the separation of the ortho and 
para mononitrotoluenes is effected more easily, and 
that little or no TNT is present. The para isomer is 
the one used for dyestuffs, and it is separated from the 
ortho and the small amount of meta by cooling the 
mixture to 10° C. At this temperature some of the 
para mononitrotoluene separates out and may be 
filtered off. If a complete separation is desired, a 
vacuum distillation of the mixture must be carried out. 
For nitration to TNT only, no separation of the three 
mononitrotoluenes is necessary. 

The second stage of the German process is very 
much like the American. The mononitrotoluene (500 
kilograms) is placed in the nitrator and sulphonated 
with 1400 kilos sulphuric acid at a temperature of 
60 to 70°. Then a mixture of 700 kilos of 100 per cent 
sulphuric acid and 700 kilos 48° Be. nitric acid, is run 
in. The mixture is agitated until a sudden drop of the 
temperature indicates the end of the reaction of nitra- 
ting the mononitrotoluene to dinitrotoluene. The 



THE MANUFACTURE OF TNT 



39 



temperature is then raised to 120°, and held at this 
point until the charge is finished as indicated by the 
control analyses. 

In some parts of Germany trinitrotoluene is made 
from dinitrotoluene, which occurs as a by-product in 
various processes of the manufacture of other materials. 
In such a case, the dinitrotoluene is melted, sulphonated 
with one and one-fourth its weight of oleum, nitrated 
with three-fifths its weight of nitric acid at tempera- 
tures varying from 100 to 130°, and finally separated 
from the spent acid, washed and crystallized. 

A good comparison of the three processes used in the 
United States may be obtained from a summary of* 
these processes : 



Acid, nitric 

Acid, sulphuric 

Yield (kilos. TNT per kilo, toluene) . 
Time (hours) 



One 

Stage. 


Two 

Stage. 


3 


2.2 


9 


5.6 


1.9 


1.99 


7 


6-7| 



Three 
Stage. 



2 
5 
2.2 

7-8 



From this summary, it is apparent that the three- 
stage process necessitates the use of less acid — and 
therefore less loss of TNT by solution — but consumes 
more time than the other two processes. The problem 
of the chemical engineer is therefore to determine the 
best equilibrium for the conditions present in his par- 
ticular plant. This calculation necessitates a knowl- 
edge of the " plant-hour " value, together with the costs 
of acids, toluene, and other materials; the cost of deni- 
zation of the spent acid, and the concentration of 
sulphuric acid. But, as a general rule, in considera- 



40 TRINITROTOLUENE 

tion of the higher grade of product turned out, the three- 
stage process may be said to be the best. 

Many engineers have investigated to the extreme 
the conditions necessary for the best yields and the best 
product possible in the manufacture of TNT. Much 
credit is due one of these investigators, M. Coparisow, 
because of the light his research has thrown upon the 
nitration of toluene, and the cure for the troubles 
encountered in this reaction. A summary of Copari- 
sow's work is given here, it being taken from a recent 
article. (3) 

" The mineral matter present during the process of 
nitration may act either as a catalyst or as a chemical 
reagent, and this action may explain some of the 
curious occurrences in the course of a nitration. Fur- 
thermore, when mineral acids act upon the metal parts 
of the apparatus, hydrogen may be set free, and may 
reduce some of the nitro-compounds. Under the 
working conditions amino groups may be diazotized 
yielding cresols and nitrocresols, whose salts are highly 
explosive, and this action may explain some of the 
heretofore mysterious accidents in TNT plants. These 
may be obtained as by-products, through the action of 
the hydrogen, and the oxidizing action of the nitric 
acid itself:" 

" 1. Trinitrobenzoic acid and tetranitromethane. 
These result from oxidation in case of overheating or 
pressure. The intense odor of the tetranitromethane 
is sometimes observed in the factories, but the trini- 
trobenzoic acid, owing to its solubility, generally 
escapes detection." 

" 2. Phenolic compounds. These, like cresols, may 
result from the reduction of the nitro-compounds by the 



THE MANUFACTURE OF TNT 41 

nascent hydrogen which is generated by the action of 
the acids upon the metal of the nitrator." 

" 3. Sulphonic acids. These compounds may result 
when the quantity of sulphuric acid is too great; 
i.e., when the mixture of acid contains too much sul- 
phuric acid in proportion to the nitric acid." 

In the process of the manufacture of TNT, Copari- 
sow points out the following as being matters requiring 
particular care and watchfulness: 

"1. The amount of nitric acid used must exceed the 
theoretical amount necessary by at least one-half 
molecule." 

" 2. The extent of the nitration should be regulated 
more by the concentration of the acids, the temperature 
and the duration of the nitration than by the actual 
quantity of nitric acid present." 

" 3. The reaction product should not be kept in 
contact with the spent acid longer than is absolutely 
necessary." 

"4. The concentration of acid and the nature of the 
material in the plant should be such as to reduce their 
action on one another to a minimum." 

" 5. The raw materials must be pure." 

Coparisow further states that disposal may be made 
of the residue from the mother liquor — which residue 
consists of a complex mixture of various dinitrotoluenes 
and trinitrotoluenes — by nitrating this with a mixed 
acid containing only 15 per cent nitric acid. By this 
method, a " liquid TNT " is obtained, which has con- 
siderable power, and has the property of gelatinizing 
collodion cotton, the same as nitroglycerine does. This 
liquid product is used in the manufacture of gelatinized 
explosives. 



42 TRINITROTOLUENE 

Following the nitration of the TNT, either one of 
two processes may be followed. The first of these 
processes consist in " blowing " the charge of TNT plus 
the spent acids to a separating pan, where the charge is 
allowed to cool. On cooling, the TNT crystallizes out, 
and so separates from the spent acid. Water is usually 
added to the mixture when it is blown, in order to more 
completely precipitate the TNT from the acid solu- 
tion. McHutchison and Wright (4) have investi- 
gated the minimum amount of water necessary to 
completely separate TNT from the mother liquor in 
order to avoid unnecessary expense in the recovery of 
the spent acids. It was found that the maximum pre- 
cipitation of TNT occurred on the addition of the acid 
to 4-5 volumes of water. A greater dilution than 
this, or the addition of the water to the acid was found 
to be less effective. Following the separation, the spent 
acid is drawn off to a tank, and may either form the 
basis for the new nitrating acid, or may be sent to 
the reclaiming plant for purification. The TNT is 
transported to the washing plant by either manual 
labor, or by melting and blowing through pipes or 
troughs. 

The second method of disposing of the completed 
nitration mixture consists in cooling the products while 
still in the nitrating kettle, and thus forcing out the 
TNT from its acid solution. This procedure, of course, 
results in more dissolved TNT in the spent acid, but 
the time saved in the separation is very great, since the 
crystallization in pans requires about four days, while 
the nitrator separation requires but a few minutes. 
The nitrator separation is used especially in plants 
where the spent acid goes into the next charge of 



THE MANUFACTURE OF TNT 43 

nitrating acids. Thus, the TNT in solution in the 
spent acid is reclaimed, so the percentage dissolved does 
not matter. 

Even after this separation of the spent acid, there 
still remains a considerable amount of acid in the TNT. 
In order to obtain a marketable product, this acid must 
all be washed out. To perform this operation, the 
TNT is blown from the separating pan or, if the separa- 
tion was made in the nitrator, from the nitrator to the 
washing tanks. The washing is accomplished by means 
of hot water (85 to 90° C.) Seven or eight changes of 
water are necessary for the complete removal of the 
acid. 

The washing of TNT was originally for the sole pur- 
pose of removing the acid and rendering the TNT neu- 
tral to litmus. This process has been extended and 
elaborated upon, until to-day, in a modern plant, the 
primary steps in the actual purification of the TNT are 
carried out in the washing kettle. Various chemicals 
have been tried in solution in the wash water. The 
one great success in this line is sodium sulphite. 
Besides acting as a neutralizing agent to the acid, the 
sodium sulphite liquor exerts a solvent action on the 
lower nitration products of toluene, and thus serves to 
remove some of these impurities from the symmetrical 
trinitrotoluene. The usual manner of using the 
sodium sulphite wash is to give first about four washes 
with hot water, then two washes with sodium sulphite 
liquor, which contains 20 kilograms sodium sulphite 
per 1000 liters water. This chemical wash is followed 
by a slightly acidified water wash, and then with two 
more pure water washes. . Various other chemicals, 
such as sodium carbonate, sodium bicarbonate, etc., 



44 TRINITROTOLUENE 

have been used with more or less success. It has 
been found that these more distinctly alkaline salts tend 
to darken the TNT, and also tend to render it unstable. 
There are, in fact, some sodium salts of TNT which 
explode as low as 160° C. 

The washing of TNT is, in short, a chemical engi- 
neering problem which often taxes to the limit the re- 
sources of the engineer. Practice has proved that the 
most efficient washing apparatus is the most simple 
in construction. As a matter of fact, the more simple 
the entire TNT plant, the better the product, and the 
most efficient the operation of the plant. One type of 
washer, a very complicated piece of apparatus, built 
of iron, containing a lead lining, and well supplied with 
baffle walls, interior wells, and valves and syphons 
galore, was at one time in use at a certain plant. This 
machine was a model of the designer's art, but was 
absolutely useless for the washing of TNT, since the 
charge generally finished up by solidifying in the various 
valves, wells, and syphons in and connected with the 
machine. This necessitated dismantling the whole 
apparatus, and the cleansing of each individual valve 
and well with live steam. Plain wood tanks have 
now replaced this machine, and are washing the TNT 
perfectly, the entire tank costing less than a new lead 
lining for the old type apparatus, and lasting from two 
to three times as long. The agitation of the TNT and 
water in this wood tank is done by means of compressed 
air or steam entering through small holes in a pipe run- 
ning lengthwise on the bottom of the tank. 

Since TNT is appreciably soluble in hot water, the 
wash water from the washing machine contains a 
comparatively large amount of dissolved TNT. In 



THE MANUFACTURE OF TNT 45 

order to reclaim this dissolved material the wash water 
coming from the washers is run through a series of 
tanks containing baffle walls to force the water to 
travel a considerable distance. This is known as the 
" labyrinth." Here the water cools, and the TNT is 
thrown out of solution. These labyrinths are cleaned 
out periodically, and the recovered TNT is melted, 
sieved, and if necessary treated with a nitrating acid 
and finished in the ordinary way. In some cases this 
reclaimed TNT (sometimes of inferior quality) is 
mixed with good TNT (" blending ") and is thus 
disposed of. The conscientious inspector of TNT will 
not allow this practice unless done under his personal 
supervision. Blended TNT possesses certain charac- 
teristics that pure TNT does not possess, and may thus 
be detected. 

Following the washing, the TNT is crystallized or 
" grained." From the washing tank or kettle the 
molten TNT is run by gravity into the crystallizing 
pan. This apparatus consists of a water-jacketed 
horizontal pan, in the center of which is set a vertical 
shaft carrying a brass or bronze arm. This shaft may 
be driven by either overhead or bottom drive. The 
under drive is preferable from the standpoint of safety, 
because in this manner of drive, all belts, gears and 
motors are placed underneath the pan where the work- 
men cannot come into contact with them. The under 
drive furthermore lessens the possibility of contamina- 
ting the TNT, which is being crystallized in the pan, 
with dropping oil or grease from the belt or gears, such 
as might occur if the drive were of the overhead type. 
The arm which is attached to the revolving shaft should 
clear the sides and bottom of the pan by at least f inch. 



46 TRINITROTOLUENE 

This is necessary to prevent friction between the arm 
and the pan, and the possibility of ignition of the 
TNT. The arm should be set in a sloping position 
with the slope downward in the direction of rotation. 
This slope causes the TNT to climb over the arm, and 
greatly facilitates the graining of the material. 

A second method of reducing the TNT to small 
particles, and which is, as yet, quite new, depends upon 
the rotation of a drum in the molten TNT. As the 
drum revolves, a thin layer of TNT adheres to it, and 
is scraped from the drum by a knife after about one- 
half revolution. This machine decreases the time 
necessary for the crystallization greatly. The process 
is known as " flaking." 

The completion of the crystallization marks the end 
of the process of manufacture of crude TNT. The only 
operation left is the screening. This is done by shovel- 
ing the TNT directly from the crystallizing apparatus 
into an oscillating screen having 10 to 30 meshes per 
inch. The TNT passing through the screen is packed 
into boxes of 100 pounds each. 

One of the problems confronting the pioneer chem- 
ical engineers in the explosive field was the disposal 
of the spent or waste acid from the nitrations. The 
analysis of a typical spent acid shows the following 
composition : 

Nitric acid 3-12% 

Water 10-30 

Organic matter ^-3 

Sulphuric acid Balance 

The disposal of this acid in the earlier plants was accom- 
plished by sending the acid directly from each nitra- 



THE MANUFACTURE OF TNT 47 

tion to the spent acid tank, and from this place to the 
denitrifying plant. Modern practice utilizes the spent 
acid from one stage as the basis of the nitrating mix- 
ture for the next preceding stage. This re-use is 
along certain lines that are developed by the individual 
plant. This method of using the spent acid over again 
possesses the following advantages: 

1. The saturation of each spent acid with organic 
matter lessens the loss of the TNT by solution. 

2. A uniform spent acid is discarded by the nitra- 
tion plant, thus enabling the denitrating plant to adopt 
a standard practice, and to treat each batch of acid the 
same. 

The first step in the reclaiming of the spent acid is 
the cooling and filtering of the acid. This removes a 
large part of the organic matter. The removal of the 
organic matter is very important, especially so if the 
recovered nitric acid is to be used in the manufacture 
of ammonium nitrate. Foreign material in the nitric 
acid may result in an explosion. In the United States 
alone, at least one explosion is known to have been 
caused by such contamination. 

Following the removal of the organic matter, the 
acid goes to the denitrating plant. Here the nitric 
acid is separated from the sulphuric acid by blowing 
air and steam through the mixture. The weak nitric 
acid resulting from the solution from the denitrating 
towers is used, as stated above, in the manufacture of 
ammonium nitrate. 

The reclaiming of the waste acid has been the object 
of several patents granted in the United States and 
foreign countries, the medium of separation being 
solvents, for the most part. A British patent (5), 



48 TRINITROTOLUENE 

granted in 1914, separates the nitrotoluenes contained 
in the waste acid by washing the acids with toluene or a 
nitrated toluene which has been nitrated to a lower 
degree than that of the products to be removed. If 
the process be carried out at a suitable temperature, 
the toluene or nitrotoluene used for the extractant 
undergoes nitration in the process. Fresh nitric acid 
may be added to the waste acids for this purpose. 

Another process of extracting the organic matter 
from the waste acids by solvent means was patented 
in 1915. (6) This process is made continuous by run- 
ning together the waste acid and solvent, in suitable 
proportions, into a mixing tank, while maintaining the 
appropriate temperature and pressure. The mixture 
flows from the mixing tank through an overflow pipe 
into settling tanks, where the liquids divide into layers, 
the nitrotoluenes formerly dissolved in the acids being 
now dissolved in the solvent. Suitable solvents men- 
tioned in the process are toluene, mononitrotoluenes, 
etc. 

A distillation process is interesting because of its 
uniqueness. In the operation of this process (7) the 
waste acid is evaporated in a suitable container, and 
the organic substances are removed from the gas and 
vapors by passing these vapors through a chamber over 
water. The part not absorbed by the water in this 
chamber passes out into a condenser. The solidified 
organic matter collects in a readily accessible chamber, 
and is removed from time to time. 

A peculiar use is made of the spent acid in some parts 
of Russia. (8) The waste acid from the manufacture 
of TNT contains 62 to 72 per cent sulphuric and 2 to 
3 per cent nitric acid. This is used to prepare super- 



THE MANUFACTURE OF TNT 49 

phosphate from the Russian phosphate rock. The 
superphosphate thus prepared is said to be much more 
dry and more pulverulent than that made with sul- 
phuric acid alone. 

After the separation of the nitric acid from the solu- 
tion, there remains a mixture of sulphuric acid and 
water. This is concentrated by running slowly through 
a series of pans, called a " cascade," which are heated 
from beneath. Various other patented processes are 
now coming into use for concentrating sulphuric acid 
solutions. The acid coming from the concentrating 
plant is mixed with oleum to further reduce the water 
content, and may be used in nitrating mixtures again. 
Another use for the acid as it comes from the concen- 
trating house is in the manufacture of nitric acid. 

Another problem which the engineer must meet is 
that of transferring the TNT after it has been completed 
by nitration to the various other stages of the manu- 
facturing process. With the toluene, acids and other 
raw materials this is comparatively easy, since these are 
in the liquid state. TNT, however, will solidify at 
80° C. and must be kept above this temperature if it is 
to be blown through pipes. Blowing consists in run- 
ning the TNT in a molten state into a strong box called 
a " blow-case," and then, by means of compressed 
air, forcing it out through steam-jacketed pipes. Con- 
siderable difficulty is experienced with this method of 
transportation, because the TNT solidifies in the pipes 
seemingly without the least reason. When such an 
occurrence takes place, it is necessary to either wait 
a considerable time until the TNT melts, which delays 
the process; or else a section of the pipe must be cut 
out, and the TNT removed mechanically. One very 



50 TRINITROTOLUENE 

good plan to overcome this difficulty is to run the TNT 
through very short pipes, by gravity, or where a short 
pipe is not feasible, a trough may be made, and sur- 
rounded by steam pipes embedded in asbestos cement 
or sand. Should the TNT solidify through accident, 
the trough can be readily cleaned out without delay or 
inconvenience. 

The oily substance which separates on the second 
stage of the three-stage process, called by the Germans 
" binitrotropfol," is quite indifferent to attempts 
made to nitrate it. The problem has been solved in 
Italy, according to Giua, in this manner: (9) 

• The oil is treated with an anhydrous acid mixture, 
within very narrow limits (1 : 2). With this treat- 
ment, a product is formed, having a melting-point of 
66° C, and which can be separated from the oily and 
more difficultly nitrated portion by cooling to 40°, 
and allowing the oil to drain off. A second nitration 
will yield a product which, on being washed, melted 
and neutralized, melts at 80° C. This " tropf " oil 
has always been regarded as useless in Italy, but in 
Germany, where alcohol is used for crystallization, 
" tropf " oil is the starting-point for much of the TNT 
produced. A single nitration of the oil does not give 
a utilizable TNT if the latter is not crystallized from 
some solvent, because 5 to 7 per cent of the oil remains 
unnitrated under ordinary conditions. The use of 
alcohol as a solvent from which to crystallize the TNT is 
prohibited in Italy, because of the high tax on alcohol. 
Denatured alcohol cannot be used, because the pyridine, 
which is used as a denaturant, darkens TNT. For 
this reason the TNT industries in Italy use dinitrotolu- 
ene as the starting-point, and the dinitrotoluene is 



THE MANUFACTURE OF TNT 51 

centrifuged to separate the oil. By the above method 
of nitrating, a great amount of this oil has been saved. 

It will be seen from the foregoing description of the 
complete manufacture of TNT that the modern fac- 
tory must be much larger than a simple nitrating, 
washing and crystallizing plant. The modern plant 
must include, besides the TNT units: (a) Plant for 
manufacturing nitric acid; (6) Sulphuric acid concen- 
tration plant; (c) dinitrating and filtering plant; 
(d) ammonium nitrate plant, or other plant to utilize 
the weak nitric acid that is recovered from the spent 
acid. 

Summing up the entire process, it is one of chemical 
control from beginning to end — from the testing of the 
toluene from which the TNT is made, to the analysis 
of the acids recovered from the waste liquors. Chem- 
ical control cannot be emphasized too greatly, and the 
plant with the most highly developed chemical control 
is the plant that turns out the best product. 



CHAPTER V 
THE PURIFICATION OF TNT 

The purification of TNT, while in reality a part of 
its manufacture, may consist of any one of a number of 
methods, most of which are equally good as a means of 
extracting the " impurities " in the TNT. There are 
appearing every day new methods of purifying this 
substance, and the number is now too great to treat 
each method separately. It is thought wise, in view 
of the fact that a differentiation is made between crude 
and purified TNT, to treat the purification as a sepa- 
rate subject, rather than to include it in the discussion 
of the manufacture. 

The product which results from the application of 
the various processes outlined in the previous chapter 
is known as " crude TNT." To define the word 
" crude " as applied to TNT is rather difficult, since 
a crude product is generally thought of as being a 
product that is contaminated with foreign substances. 
The purified product differs from the crude product in 
that these foreign matters are removed. As a matter of 
fact, " crude " TNT contains no real impurities, in the 
true sense of the word, because the impurities have been 
removed in the washing of the crude product. There 
are, it is true, other compounds of nitric acid and tol- 
uene (the lower nitration products), in the TNT, and 

52 



THE PURIFICATION OF TNT 53 

these are the " impurities " meant when this term is 
used in connection with TNT. 

By referring to the chapter on " The Nitration of 
Toluene " it is seen that TNT may contain mono- 
nitrotoluene, dinitrotoluene and even other isomeric 
trinitrotoluenes aside from the symmetrical TNT. 
The common expression " TNT " (or its synonyms) 
has become narrowed down to mean that certain 
trinitrotoluene isomer defined as the alpha, or 1-2-4-6 
isomer. The melting-point of this particular trinitro- 
toluene as determined by reputable authorities is 
80.6 to 80.8° C. Now, if other trinitrotoluenes or any 
mono- or dinitrotoluenes be mixed with the symmetrical 
TNT, the melting-point will be either raised or lowered, 
according to the specific nitrotoluene present. As a 
general rule, the melting-point of the mixture is lower 
than the melting-point of pure TNT, indicating the pres- 
ence of some of the mono- and dinitrotoluenes. In 
order to remove these compounds from the TNT, 
many different methods of purification are resorted to. 
The greater number of these methods depend upon the 
solvent action of some substance upon the mononitro- 
toluenes and the dinitrotoluenes. The more important 
of these methods are outlined below. 

1. The Purification by Alcohol. The crude TNT 
is placed upon the filter medium of a vacuum filter. 
An amount of 180 proof alcohol, equal in weight to 
one-quarter the weight of the TNT, is added. This 
mixture of TNT and alcohol is then agitated thoroughly, 
and fresh alcohol, equal to one-half the weight of the 
TNT is poured in on top of the mixture. The filter 
pump is then started, and the alcohol is filtered off 
until the top level of the alcohol layer is coincident 



54 TRINITROTOLUENE 

with the top of the TNT. At this point a further 
amount of alcohol equal to one-quarter the weight of 
the TNT is added, and the filter is sucked dry. The 
TNT is dried by either a current of warm air, or by 
vacuum. In the latter case, the filter must be so ar- 
ranged that a vacuum may be effected in the upper 
chamber. 

The action of the first portion of alcohol added is 
to dissolve the mononitrotoluenes and the dinitro- 
toluenes. The second volume added dilutes this solu- 
tion and dissolves any of the nitrotoluenes which 
escaped solution by the previous addition. The last 
portion of alcohol serves to dissolve out any remaining 
traces of the impurities, and also serves to wash the 
TNT. 

The cost of this method of purifying TNT is rather 
high. Pure ethyl alcohol is preferable to denatured 
alcohol, because of the action the denaturing agents 
have on the TNT. The cost of the undenatured sol- 
vent is too high, however, to permit its use unless a 
well-developed plan of solvent recovery is in operation, 
so that practically none of the solvent is lost. 

2. Purification by Sulphuric Acid. Hot sulphuric 
acid, 100 per cent concentrated, possesses the property 
of dissolving all three classes of the nitrotoluenes. Upon 
cooling such a solution, the trinitrotoluene crystallizes, 
but the mono- and dinitrotoluenes remain in solution. 
This property of sulphuric acid forms the basis of an- 
other method of purifying TNT. The solution of the 
TNT in the sulphuric acid is effected in steam-heated, 
lead-lined vats. The liquor is then filtered and cooled. 
The recrystallized TNT must be washed with several 
changes of water to remove the acid. This method 



THE PURIFICATION OF TNT 55 

of purifying TNT yields a very light-colored product. 
The loss of TNT is quite high, since about one-third 
the total amount of TNT remains in solution. The 
spent acid from this purification which contains the 
dissolved mono- and dinitrotoluenes may be used 
either as a sulphonating acid, or as the sulphuric acid 
portion of a nitrating acid. 

A modification of the sulphuric acid process has 
been patented (1) when applied to a mixture of mono- 
nitrotoluenes and paraffin hydrocarbons. The nitra- 
tion of the toluene is carried on carefully so as to take 
it only as far as the mononitrotoluene. The mono- 
nitrotoluene is dissolved in sulphuric acid, but any 
paraffins that may be present will not dissolve, and will 
form a separate layer. A separation of these two lay- 
ers and the subsequent nitration of the sulphuric acid 
solution of mononitrotoluene yields a very high grade 
TNT. Thus a toluene containing a comparatively 
large percentage of paraffins may be utilized in the 
manufacture of TNT. 

3. Carbon Tetrachloride and Alcohol. A mixture 
of carbon tetrachloride and alcohol exerts a marked 
solvent action on the two lower nitro-compounds of 
toluene, and this action forms the basis of a patent 
granted for the purification of TNT. The proportions 
of the solvent used vary, certain conditions requiring 
particular concentrations of the two solvents. For the 
use of this solvent an especially designed filter is needed 
which will allow the mixture of TNT and the solvent 
to be thoroughly agitated directly on the filter medium. 
The method of operation is practically the same as that 
used for the purification by alcohol alone. The vacuum 
filter is so arranged that when the last layer of solvent 



56 TRINITROTOLUENE 

has been added, and the filter sucked dry, the apparatus 
may be reversed and used as a vacuum drier. Hand- 
ling of the TNT is thus reduced to a minimum. This 
method is said to be very efficient, the loss being only 
3 to 7 per cent. The cost per kilogram TNT is reported 
to be about 6 cents. 

4. Purification by Sodium Sulphite. One of the 
cheapest and probably one of the best methods of 
accomplishing the purification of TNT by solvent 
means is by the use of a 20-per cent solution of sodium 
sulphite. Various methods of using this solution have 
been developed, the two best of these being given: 

The first method consists in agitating the TNT with 
the hot sodium sulphite solution until the mono- and 
dinitrotoluenes are in solution, then cooling and 
allowing the TNT to solidify in the usual way. The 
second method consists in adding the molten TNT to 
the sulphite liquor in a very fine stream. The tem- 
perature of the sulphite solution should not be so low 
that any of the mono- or dinitrotoluenes may escape 
solution, but, on the other hand, should not be higher 
than the melting-point of the TNT. The TNT solidi- 
fies in the form of small balls or pellets, and because 
of this action, the process is known as " pelletilizing." 
Of course, the solution used in the pelletilizing process 
need not be sodium sulphite, as other solutions will 
bring about the same result. 

The use of sodium sulphite as a purifying agent 
for TNT always necessitates a wash with 1 or 2 per 
cent sulphuric acid after the sulphite treatment, in 
order to remove the dark color which is imparted to 
the TNT by the sulphite. Following the sulphuric 
acid wash, two fresh water washes should be given. 



THE PURIFICATION OF TNT 57 

The sodium sulphite method of purifying TNT is 
very cheap; the figure given by one large producer of 
TNT is tV cent per kilogram. This firm, it is said, 
obtains the sulphite from the waste liquor of the hy- 
droxide fusion in the manufacture of phenol. Assum- 
ing the above statement to be true, the cost of purifica- 
tion per kilogram TNT will be somewhat higher if it 
were necessary to purchase the sulphite. The salt 
need not be chemically pure for this purpose, but it 
should not contain appreciable quantities of the 
hydroxide, carbonate or other distinctly alkaline salts, 
since these salts will darken the TNT so deeply 
that the sulphuric wash may not restore the light 
color. 

5. Mechanical Purification. A very interesting 
method of purifying TNT is in use at the plant of one 
of the largest producers of TNT in the United States. 
This process comes nearer to that used by the Germans 
than does any other American process. It will be 
remembered that in the second stage of the nitration 
a mixture of mono- and dinitrotoluenes forms as an 
oil. The procedure involved in this method is to 
centrifuge the dinitrotoluene and in this manner remove 
this oil. It is said that the oil obtained in this process 
may be further nitrated to TNT, but according to 
Giua and Molinari, and Nolting and Witte, the oil 
consists mostly of meta mononitrotoluene and dinitro- 
derivatives of the same. Will and others insist that 
some of these derivatives at least are not capable of 
being further nitrated without undergoing decomposi- 
tion, or not without great difficulty. The TNT formed 
by the nitration of the thus purified dinitrotoluene 
possesses a melting-point of 80° C. 



58 TRINITROTOLUENE 

6. Modified Solvent Process. Still another inter- 
esting process is a modification of the sulphuric acid 
solvent method. This method has gained favor with a 
number of manufacturers because of its time-saving 
qualities. The procedure with this method is to add 
100 per cent hot sulphuric acid to the mixture of TNT 
and spent acid immediately after the nitration is com- 
pleted. The mono- and dinitrotoluenes together with 
most of the TNT dissolve in the sulphuric acid, the 
mixture is cooled and filtered, and the TNT recovered. 
This process possesses the advantage of eliminating one 
washing, and is thus to be preferred to the ordinary 
sulphuric acid treatment as outlined above. The 
spent acids may be used in subsequent nitrations, and 
the dissolved organic matter recovered in this manner. 

Many other solvents may be used to accomplish 
the purification of TNT. The organic solvents such 
as toluene, acetone, etc., find an especially wide 
application. The method followed with these solvents 
may be either a simple heating of the mixture of TNT 
and solvent until the impurities dissolve, followed 
by cooling and crystallization of the TNT, or it may 
be a more elaborate scheme somewhat as outlined in 
method 1 above. Well-developed processes have been 
worked out for purifying TNT by solvent means 
using nitrobenzene and nitrotoluene as the solvents. 
The solvents may be purified for further use by dis- 
tillation with steam. (2) 

The recovery of the solvent is a very important con- 
sideration in an efficient plant. This recovery must be 
carried out with a great deal of care, since the concentra- 
tion of the nitro-derivatives in the solvent increases 
as the solvent is distilled off. If the distillation is 



THE PURIFICATION OF TNT 59 

carried too far, the nitro-compounds may decompose 
with explosive violence. Two cases are recalled where 
explosions have resulted from an attempt to carry the 
distillation of the solvent used for extracting the mono- 
and dinitrotoluenes to a too-concentrated residue. 
The solubility of the mono-, di- and trinitrotoluenes in 
the hot solvent is naturally greater than in the cold 
solvent. Therefore, although the boiling solvent may 
exhibit no signs of being saturated with the nitro- 
compounds, it may be near the danger point. The 
procedure followed by the writer in solvent recovery 
is to distill the solvent until the volume of the recovered 
solvent is equal to one-half the volume of the solution 
placed in the still. At this point the distillation is 
interrupted, and the residue, which is twice as concen- 
trated as it originally was, is withdrawn from the still 
and allowed to cool, when the excess of dissolved sub- 
stances will be thrown out of solution. The mixture 
is then filtered, and the concentration will be just the 
same as at the start of the operation. To illustrate: 
Suppose a volume of 1000 liters of solvent saturated 
with 6 per cent dissolved nitrotoluenes is to be re- 
covered; 500 liters, say, of the solvent are placed 
in the still, and 250 liters distilled off. The residual 
liquid in the still now contains 12 per cent dissolved 
organic matter. On cooling, one-half this solute will 
precipitate, and after filtering the cold mixture, 
the solvent concentration will be the same as it 
originally was, —6 per cent. The remaining 250 liters 
may now be mixed with another 250 liters of the 
fresh solution and the process continued. It is not 
probable that the concentration of the residue at the 
point where the distillation is interrupted is very close 



60 TRINITROTOLUENE 

to the decomposition point, but with the operation 
outlined it costs nothing to be on the safe side, and 
practically 100 per cent solvent recovery, barring evap- 
oration or carelessness, may be accomplished. 

The still which is used for the recovery of the sol- 
vent may be a steam- jacketed still of almost any shape 
for the lower boiling-point compounds. For those 
solvents whose boiling-point is higher than that of 
water a direct fired still, or one supplied with high 
pressure steam, is necessary. In cases where simple 
solvents such as alcohol or acetone are to be recovered 
a simple still without any column will do very nicely. 
If the solvent is complex; that is, if it is composed of a 
mixture of two or more solvents, and these solvents 
must be separated, a more complicated still with a 
fractionating column is necessary. In this period 
of modern engineering skill, a special still designed and 
built expressly for the one particular purpose for which 
the manufacturer desires it, can be bought for very little 
more than a stock still, and will perform its work much 
more satisfactorily. 



CHAPTER VI 
THE INSPECTION AND TESTING OF TNT 

By K. K. Stevens 

Inspection. TNT is on the market in two grades, 
primarily, crude and refined. The crude has not been 
recrystallized from solvents, while the refined has. Of 
these two grades, there may be several other grades 
based on the melting-point (M.P.) or usually the 
solidification point (S.P.). 

The crude TNT is the more common form in the 
United States and when purchased by foreign govern- 
ments is shipped crude and either refined or blended 
with other substances. The greater bulk of TNT made, 
up to very recently, has been shipped crude, possibly 
only three plants in the United States manufacturing 
the refined grade in any quantity. In the different 
plants the product is obtained in lots of approximately 
2200 pounds each, called " runs." 

The specifications usually call for containers, such 
as cases or kegs, which hold from 60 to 100 pounds, 
are lined with oiled paper, and numbered as to ship- 
ment, " run " and case. The inspector may be ex- 
pected to check the weights, and take samples for 
analysis. 

Sampling. Samples should represent lots of 4000 
pounds, and for convenience a composite sample from 
two runs is often taken. The cases are selected, opened, 

61 



62 TRINITROTOLUENE 

and the samples taken from different parts of the case, 
mixed, and three 1-pound bottles filled; one each for 
buyer, seller, and referee, the latter's bottle being 
sealed by the buyer's inspector. 

Testing. Color should be light yellow for crude, 
cream for refined. 

Comment. The color changes rapidly when exposed 
to strong light, sunlight changing it from yellow to 
orange in fifteen to twenty minutes, although the deeper 
shades of yellow are not an indication of impurity. 
The brownish grades should be inspected, though not 
necessarily condemned in the crude grade without con- 
firmatory tests. 

In the refined grade the color may vary with the 
solvent used in recrystallizing, but should usually be 
of a light cream, melting to a clear light brown, not 
darkening appreciably at 100° C. for two hours. 

Fineness. For crude, 90 per cent shall pass 
through a 10-mesh sieve. For refined, 99 per cent 
shall pass through a 12-mesh sieve. For exploders, all 
shall pass through a 30-mesh sieve. 

Comment. The crude may contain frequently 7 to 
8 per cent of lumps larger than specified, but is usually 
O.K., always being sieved before packing, and the lumps 
forming on the sides of the crystallizing tub have been 
allowed, intentionally or accidentally, to get in the 
sieved product. 

Moisture. Moisture shall not be more than 0.10 
per cent for crude or refined (some specifications allow 
0.15 per cent) and shall be determined by drying 
2 g. over sulphuric acid for twenty-four hours. 

Comment. The method is efficient, and will remove 
as much as 30 per cent moisture in the time specified. 



INPSECTION AND TESTING OF TNT 63 

Acidity. There must be no acidity. This deter- 
mination is made by shaking 10 g., melted, with 100 
c.c. boiling water (distilled) allowing to cool, pouring 
off the water extract into a flask, and reserving; the 
operation is repeated with 50 c.c. distilled water, adding 
the second extract to the first. The combined extrac- 
tion is titrated with N/20 caustic alkali, using phenol- 
phthalein as indicator. 

Other specifications less definite are as follows: 
Shake 5 g. with 100 c.c. distilled water in a 100-c.c. 
graduated cylinder one minute, adding blue litmus 
paper and stand thirty minutes, with occasional shak- 
ing. The paper must not show any acid reaction at the 
end of this time. 

One specification allows 0.03 per cent acid calcu- 
lated as sulphuric. 

Comment. The method of the first specification 
seems better, although any sodium bicarbonate wash- 
ing (not used at present) will give acid reaction at 
this point, whereas methyl orange will give only the 
mineral acids. The litmus paper shows acidity with 
phenolic compounds as well as acids, but if the deter- 
mination is carried out as specified, there will be no 
color to the litmus paper, it having been completely 
bleached, and any acid reaction is more or less doubt- 
ful. The method may be modified as follows: Shake 
5 g. with 400 c.c. distilled water one minute, filter, 
stand 5 minutes and add the litmus paper; any acid 
reaction will be detected in two minutes. The litmus 
might be used instead of titrating in the first 
method. 

Insoluble matter must not exceed 0.15 per cent, 
as determined by boiling 10 g. with 150 c.c. of 95 per 



64 TRINITROTOLUENE 

cent alcohol, collected on a weighed Gooch crucible, 
washed with not more than 150 c.c. of 95 per cent al- 
cohol, drying at 95° C. one hour and weighing. 

Some specifications call for benzene as the solvent 
and allow 0.10 per cent for refined, 0.15 per cent for 
medium, and 0.20 per cent for crude. 

Comment. The method is efficient. 

Turbidity in the wash water is one cause for high 
insoluble matter, and another cause is allowing the 
TNT to stand too long in the lead-lined wash tanks, 
the acid attacking the lead and forming lead salts. 

Ash in crude TNT must not exceed 0.10 per cent, 
determined by igniting 1 g. in a platinum crucible, 
allowing to burn slowly and igniting completely, pre- 
caution being taken to prevent loss of ash. 

Comments. The sample should be heated, ignited 
directly with the flame, and allowed to burn without 
first melting; if melted and then heated further, the 
sudden combustion will expel it from the crucible. 

The size of the sample should be about 2 grams, 
taking into consideration the low percentage of ash 
present. 

The residue called " insoluble matter " might be 
conveniently used for the ash determination. 

Some specifications call for sulphated ash, probably 
to avoid loss of potassium or sodium salts during 
ignition. 

Ash in refined TNT for exploders must be less 
than 0.05 per cent. 

Nitrogen. Crude TNT must contain not less than 
18 per cent nitrogen determined by the Dumas combus- 
tion method. 

Refined TNT must contain not less than 18.20 



INSPECTION AND TESTING OF TNT 65 

per cent nitrogen determined by the Dumas combus- 
tion method. 

Comment. The Dumas method, standard for nitro- 
gen, requires little comment, results being very satis- 
factory, although it is necessary to make determina- 
tions on a substance of standard nitrogen content. 

The method requires from one and one-half to 
three hours, and unless the chemist possesses several 
furnaces, not very many determinations can be made 
daily. 

For the nitrogen determination on many organic 
compounds, the Gunning-Arnold method or modifica- 
tion of it has been used. The only modifications 
reported to be satisfactory for trinitrotoluene or other 
nitro-compounds are the zinc dust reduction by W. C. 
Cope, U. S. Bureau of Mines, and the use of nitron 
as reagent by W. C. Cope and J. Barub. (1) 

The nitrogen determination is important, although 
if the melting-point or solidification point is up to 
specification, the nitrogen is seldom below. 

In many instances it is common practice to average 
several samples for the determination of nitrogen. 

Diphenylamine Test. Crude TNT shall contain 
no products which will give the nitric acid reaction with 
a sulphuric acid solution of diphenylamine. The deter- 
mination is made by shaking with 50 c.c. distilled water 
in a graduated glass-stoppered cylinder, standing fifteen 
minutes, filtering and testing a few drops of the filtrate 
by adding to the diphenylamine solution. No nitric 
acid reaction should be obtained. 

Comments. The blue color characteristic of this 
reaction is readily recognized and the test is extremely 
delicate. 



66 TRINITROTOLUENE 

Care must be taken that vessels are free from traces 
of nitric acid or nitrates. 

Since other oxidizing agents, such as chlorine, 
chlorates, bromates, etc., will respond to this test, it 
is of more value, as a negative test, and fairly posi- 
tive, because the oxidizing substances mentioned are 
not likely to be found in trinitrotoluene. A pale blue 
color is not confirmative; the color should be a deep 
blue. 

Melting-point. The melting-point of crude TNT 
must be 75.5° C. or higher. 

Note. This is the mean, some specifications calling for a 
melting-point of 74.5° C. others 76.5° C. 

Medium TNT must have a melting-point of 79.5° 
to 81.5° C. 

Refined TNT for exploders must melt from 80° 
to 81.5° C. 

Comments. Methods for obtaining melting-points 
are not usually given in the specifications, but it is 
absolutely necessary that a definite procedure and 
definite apparatus be agreed upon. The following 
points should be taken into consideration: calibration 
and stem correction of thermometers, size of tubes, 
amount of substance taken, rate of melting and vessel 
of liquid to be used as bath. 

The following is given by H. B. P. Humphries, 
engineer : 

Apparatus and Method. A beaker of 1500 c.c. 
capacity should be filled three-quarters full of distilled 
water, heated by an adjustable Bunsen burner, arranged 
with a mechanical stirrer with the center of the blade 
level with the thermometer bulb, clearing it by | inch. 



INSPECTION AND TESTING OF TNT 67 

The thermometer should be graduated in tenths of a 
degree, and lowered so that the bulb is one-third the 
height of the beaker from the bottom and 1 inch from 
the side. 

Tubes should be made from thin walled 6-inch by 
^-inch test tubes drawn out into iV inch internal 
diameter, cut into 3-inch lengths, and sealed at 
one end. 

Set stirrer going and heat rapidly until temperature 
is about 15° below the melting-point. Meanwhile 
introduce a f to f-inch column of the powdered sample 
(previously dried to remove moisture) into a tube 
and tap and tamp down gently. Attach the tube to 
the thermometer by a rubber ring so that the center 
of the column of material is level with the center of 
the thermometer bulb, and replace thermometer as 
before. Reduce the heat so that the temperature 
rises 1° in two or three minutes. The slower rate 
should be adopted if several determinations are to be 
made at the same time. 

Readings. Note the temperature when: 

(a) The first globule of melted material is observed ; 

(b) The material is half molten and half unmelted; 

(c) The melting is complete and the clear liquid 
is obtained in the tube. 

Record these readings, and call (6) the uncorrected 
melting-point. 

Corrected M.P. Correct the readings for exposed 
mercury stem as follows: While the thermometer is 
registering the approximate melting-point, place a drop 
of melted diphenylamine on the stem and allow to 
flow down. For a small distance above the water 
surface the diphenylamine will remain molten; above 



68 TRINITROTOLUENE 

this it will solidify. Note the point separating the 
solid from molten diphenylamine. 

Then, if iV-number of degrees of mercury stem ex- 
posed above this point. 

T a surrounding air temperature, and T m melting- 
point, the correction is, N(T m -T a ) X0.000154. 

Add this correction to the recorded temperature 
(6) for the corrected M.P. 

The grading of the TNT being almost entirely de- 
pendent upon this determination, the method should 
be carefully followed. 

Comments. The tubes above mentioned seem too 
large in diameter, and a tube 1 mm. or less in diameter 
would give a result closer to the real melting-point. 

One quarter of an inch of the substance is enough, 
because the higher the column, the more difficult it is 
to decide when half is melted completely since this com- 
pound does not always melt in one place in the tubs, 
but often at the top and bottom simultaneously and it 
is left to the operator's judgment, at which point the 
reading is to be taken. 

The three readings are taken as a check upon each 
other. 

Solidifying-point. The uncertainty of the M.P. 
is avoided to a great degree, when the solidifying-point 
is determined. Only one set of specifications gives the 
method which is given by E. M. Weaver, Brig. General 
U.S.A. and Chief of Coast Artillery, in his book on 
" Notes on Military Explosives." 

Method. Place 200 to 250 g. TNT in a dry 
porcelain dish of 15 cm. diameter and 500 c.c. capacity. 
Melt below 90° C, remove heat and stir with thermom- 
eter. The temperature falls gradually until TNT 



INSPECTION AND TESTING OF TNT 69 

begins to crystallize, when it rises. Continue stirring 
until the highest temperature is reached. This is the 
solidifying-point. 

Comments. This determination is more apt to give 
consistent results, and is simple enough so that the 
different operators usually check closely. 

It is more accurate, since a larger sample is used, 
and the point of taking the reading more defined than 
in the M.P. determination. 

The above method is followed, without adhering 
to the size of the dish. The majority of chemists use 
a smaller dish, or test tubes and beakers without 
varying results. 

Although the M.P. and S.P. are generally considered 
the same, there is some difference, reports from differ- 
ent chemists showing the S.P. to be in some instances 
higher and in others lower than the M.P. Some 
report identical results for the two. 

The writer (Mr. Stevens) has noted that where the 
M.P. was higher the TNT had been dried at 50° C. 
and where lower, the undried sample had been used. 
Further evidence is necessary for a decision on this 
point. 

Stability tests are not usually required on crude 
material, although some specifications have required 
it on refined as follows: 

About 3 g. of the substance is placed in a 6-inch 
test tube having a strip of potassium iodide starch 
paper suspended on a glass hook which passes through 
the stopper. The tube with contents is placed in a 
bath and heated to 65° C, for from fifteen to thirty 
minutes (depending on specification). No blue color 
showing presence of nitrous acid should develop. 



70 TRINITROTOLUENE 

This last is the " Abel " heat test, usually used on 
less stable nitro-compounds. 

Since the above paper was written, many short 
cuts and improvements have been made in the methods 
of analysis. The more important of these are: 

Diphenylamine Test. Much difficulty was encoun- 
tered in this test, because of the low concentration 
of the oxidizing substances (nitric acid) and also 
because of the dilution of the blue color when a 
positive test was obtained ; therefore the following mod- 
ification was developed and adopted by at least one 
government as official. 

The TNT is shaken with 50 c.c. distilled water in a 
stoppered cylinder, allowed to stand fifteen minutes, 
filtered, and 1 c.c. of the filtrate added to a similar 
volume of a 2-per cent solution of diphenylamine in 
concentrated sulphuric acid; by pouring the filtrate 
cautiously down the side of the tube. The two solu- 
tions should not mix, but should form a two-layer 
system. If any nitric acid or other oxidizing substance 
is present, a blue ring will develop at the junction of 
the two layers. This modification is more delicate than 
the original method, because when the two solutions 
are kept apart, any blue that develops may be readily 
seen, since it is concentrated at one point and not 
diffused through the solution. This modification also 
removes danger of bleaching the blue color by the heat 
caused by the mixing of water and sulphuric acid. 
While it is true that there is a slight amount of heat 
generated at the junction of the two layers, yet this 
heat is nothing near that which results from the 
actual mixing of the two solutions. 



INSPECTION AND TESTING OF TNT 71 

A pale blue ring is really not significant because of 
the extreme sensitiveness of the test. In fact water 
often contains sufficient oxidizing agents to produce 
a quite deep blue color. One case is recalled where 
double distilled water produced a test with diphenyla- 
mine when the test was applied in the above manner. 
To be absolutely sure of results, the water should be 
distilled once in the ordinary manner, then should be 
distilled with an alkaline solution of permanganate. 
Even with this precaution, the water should always be 
tested; or in other words a blank should be run along 
with the determination. 

Another possible source of error in the diphenyla- 
mine test is in the sulphuric acid used to make the test 
solution. In many cases I have found the sulphuric 
acid to contain sufficient oxidizing substances to turn 
the entire test solution itself a deep blue. Obviously, 
such a solution cannot give accurate results. The test 
solution, when properly prepared is water white in 
color. 

Melting-point. An excellent modification of the 
apparatus used for the determination of the melting- 
point which is described by the writer of the foregoing 
methods of analysis of TNT, consists in enclosing the 
thermometer, which of course carries the melting-point 
tube, in a glass tube, closed at one end and which 
extends into the heating bath as outlined above. This 
tube should be long enough to enclose the thermometer 
to such distance as the mercury column may rise. This 
procedure provides an air bath for the mercury column ; 
the sample being included, and renders corrections for 
the exposed stem really unnecessary, since with this 
modification the correction is so small as to be negli- 



72 TRINITROTOLUENE 

gible. The adoption of the air baih for the thermome- 
ter is furthermore an assurance that the chemist will 
watch his determination very closely, for this reason: 
The temperature of the water outside the air bath may 
easily be 5 to 8° in advance of the temperature inside 
the tube. If the water is heated too fast, therefore, 
the temperature of the thermometer will rise speedily 
above the melting-point of the TNT, and this rate of 
rise will be too great for the operator to note the three 
points which determine the melting-point. The rate 
of rise of the thermometer is now officially ro° per 
minute. This insures close watch upon the part of 
the chemist, and if he be conscientious in his work, 
the various determinations will check to rs°. Fur- 
thermore, the danger of superheating is eliminated by 
the slower rate of heating. Concerning the three points 
which are taken as the melting-point reading, it has 
been said that these three temperatures are taken for the 
purpose of insuring the operator's close attention during 
the entire melting. One thing I have noticed is that 
chemists are inclined to slight the melting-point deter- 
mination; that is, to perform it in a " don't care " 
manner. Anything or any modification that will 
insure the chemist's attention, while not lessening the 
accuracy of the method is well worth while in any lab- 
oratory. 

A new test that has recently been imposed on TNT 
is an analysis of the ash for heavy metals, especially 
lead. This determination is considered necessary be- 
cause of the use of TNT with picric acid. This latter 
explosive forms an especially unstable compound with 
lead, and for this reason the metal must not be present 
even as traces. Lead may creep into TNT through 



INSPECTION AND TESTING OF TNT 73 

allowing the acid TNT to stand in lead-lined tanks for 
a considerable period of time, or through insufficient 
washing. In connection with the above statement and 
requirement an analysis of the ash of TNT which was 
carried out for the purpose of determining the amount 
of sodium present in the ash, is interesting. It was 
found that some of the TNT offered for inspection was 
quite unstable, even exploding on attempting to ash 
it in the determination of the ash. It was suspected 
that some sodium compound of the TNT existed in the 
material, and that this was what was causing the 
trouble. The possibility of the sodium compounds 
remaining in the TNT from insufficient washing after 
the chemical wash was realized, and the determinations 
were carried out in such a manner as to retain all the 
sodium in the ash. Some difficulty was encountered 
from the tendency of the TNT to ignite suddenly — 
a miniature explosion, in fact — and blow the entire 
mass out of the crucible. This occurred, it was found, 
at a temperature of about 155° C. Therefore a very 
large crucible with a cover supported by a glass tri- 
angle was tried, and was found to be perfectly satis- 
factory. The ash analysis on two samples showed 
the following percentages. (See page 74.) 

The various compounds of sodium are the result of 
the ignition (in ashing) upon the impure salts used in 
washing. The iron and silicon no doubt result from 
the action of the acid upon the nitrating kettle, which 
is usually of a high silicon cast iron. 

The results indicate insufficient washing in both 
cases, and the percentage of sodium is no doubt high 
enough to cause the trouble encountered. 

The Trauzl lead block test for TNT and other ex- 



74 



TRINITROTOLUENE 



No. 1. 



Sample weighed 500 grams 
Ash weighed .1615 gram 
Percentage of ash .0323 



Compound. 


Weight, 
Grams. 


Per Cent 
of Ash. 


Per Cent 
in TNT. 


Weight of N a, 
Grams, 


Na 2 

Na 2 S0 4 


.0088 
.0019 
.00539 
.00744 
.07369 
.06420 
Trace 


5.45 
1.17 
3.34 
4.61 
45.63 
39.76 

.04 


.001780 
.000380 
.001078 
.001488 
.014728 
.012440 


.0065300 
0006052 


Na 2 CO 


. 0023433 


Na 2 S 


.0044640 


Fe 2 3 




Si0 2 

Lead 

Undetermined 


» 



Total weight of sodium .0139425 gram. 
Per cent sodium in ash 8.67. 
Per cent sodium in TNT .0028. 



No. 2 



Sample weighed 500 grams 
Ash weighed .0335 gram 
Per cent ash in TNT .0067 



Compound. 



Na 2 

Na 2 S0 4 

Na 2 C0 3 

Na 2 S 

Fe 2 

Si0 2 

Lead 

Undetermined. 



Weight, 
Grams. 



.0024 

.000549 

.0053 

.00109 

.02148 

.00266 

Trace 



Per Cent 
of Ash. 



7.16 

1.64 
15.80 

3.27 
64.12 

7.94 

.07 



Per Cent 
in TNT. 



.00048 

.000199 

.00106 

.000218 

.004926 

.00532 



.0018 
.00018 
.00230 
.00065 



Total weight of sodium .00493 gram. 
Per cent sodium in ash 14.71. 
Per cent sodium in TNT . 000986. 



INSPECTION AND TESTING OF TNT 



75 



plosives is a measure of the power of the explosive to 
enlarge a hole in a certain size block of lead. The 
method of performing this test consists first, in pre- 
paring lead cylinders 200 mm. in height and 200 mm. 
in diameter. In the axis of the cylinder is a hole 
125 mm. deep and 25 mm. in diameter. These cylin- 
ders are prepared from the finest grade of refined soft 
lead. The casting is made in a mold which casts the 
central hole as well as the cylinder, thus eliminating 
errors from drilling. For comparative tests on various 
explosives, the blocks for the several tests should be 
made from one melt and should be cast at the same 
time. After casting, the blocks should be allowed to 
stand until they have acquired a uniform temperature 
of 15 to 20° C. The charge for the test is made up of 
10 g. of the explosive, carefully weighed out, and then 
wrapped in a piece of tin foil of the size and shape shown 
in the illustration. 






-120mm.- 



-loOmm.- 



J 



This tin-foil wrapping should be made of foil weigh- 
ing 80 to 100 g. per square meter. The charge is 
wrapped in such a manner that a cartridge of the exact 
size as the diameter of the hole is formed. After the 
cartridge is completed, an electrically detonating charge 
of 2 g. is inserted in the center of it, and the whole is 



76 TRINITROTOLUENE 

pressed into place in the lead block. Fine dry sharp 
sand of 30 mesh or finer is tamped in on top of the car- 
tridge to fill the hole. The charge is then fired, and 
after firing, the lead block is inverted and any residue 
is removed with a brush. The hole is then filled with 
water, the volume of the water measured, and the 
volume of the original cavity is subtracted from the 
final volume. The result expresses the power of the 
explosive. 

The Trauzl test is very good for explosives of the 
TNT class. TNT itself gives a Trauzl test of 290 c.c. 
This figure will vary somewhat with the lead used, and 
with the operator. 

Many other tests have been invented for the deter- 
mination of the power of explosives. One of these 
depends upon the amount of sand which is crushed 
by the explosion of a certain amount of the explosive. 
Another depends upon the compression of a piece of 
metal by the charge of explosive being placed on top 
of the metal and then exploded. In all probability 
the Trauzl test gives as good a comparative test as 
any other method, and it is easily performed, is not 
expensive, nor dangerous. 



CHAPTER VII 

THE PHYSICAL AND CHEMICAL PROPERTIES 
OF TRINITROTOLUENE 

The physical and chemical properties of the first 
three trinitrotoluenes — the alpha, beta and gamma — 
are quite well known, since these isomers have been 
known for some time, and have been prepared in suf- 
ficient quantities to enable research, which has em- 
braced many reactions, to be carried out. The last 
three trinitrotoluenes — the delta, epsilon and zeta — 
have been discovered in too recent years to enable the 
scientist to reach definite conclusions concerning their 
chemical reactions. Practically all that is known con- 
cerning these last three isomers is the melting-point. 
So far as the commercial manufacture of TNT is con- 
cerned, the chemical and physical properties of the 
alpha, beta, and gamma trinitrotoluenes are of vastly 
more importance than the properties of the others, 
because the first-mentioned isomers constitute prac- 
tically 100 per cent of the TNT. Narrowing down the 
relative importance still more, it is found that interest 
has centered on but one of the six trinitrotoluenes — 
the alpha. This is because the alpha or symmetrical 
trinitrotoluene forms about 98 per cent of the com- 
mercial product and the reactions of this product are 

77 



78 



TRINITROTOLUENE 



governed almost entirely by the reactions of the above- 
mentioned isomer. 

The structural formula of the six trinitrotoluenes 
may be designated thus : 



Alpha 



2 N 



CH 3 



N0 2 



N0 2 



Beta 



CH 3 



N0 2 



N0 2 
N0 2 



CH 3 



Gamma 



2 N 



NOs 



N0 2 



Delta 



CH 3 



2 N 



N0 2 



NO; 



Epsilon 



CH 3 



2 N 



\y 



NOs 



Zeta 



CH 3 

2 N // ^N0 2 



\^ 



NO; 



The melting-point of the alpha trinitrotoluene has 
been the subject of much discussion. The earlier 
chemists determined the melting-point of this isomer, 
and finally concluded that it melted at 82° C. More 
recent research on this subject indicates that the true 
melting-point is lower than that figure. Many chem- 
ists are loath to accept the lower melting-point because 
in several cases TNT has been prepared that melts 
at just about 82°. It must be remembered, however, 
that the commercial product contains, aside from the 






PROPERTIES OF THE TRINITROTOLUENES 79 



alpha trinitrotoluene, varying quantities of both the 
beta and gamma isomers. Moreover, the melting- 
point of both these last isomers is considerably higher 
than that of the alpha. It seems logical to assume, 
in view of this fact, that the higher melting-point of 
the product is due to the presence of the beta and 
gamma trinitrotoluene. In any case if these two 
isomers were present in the form of " impurities," 
they would certainly exert some influence on the melt- 
ing-point, and since the highest melting-point that 
has been obtained is 82° C, it is entirely logical to 
assume that the melting-point of pure alpha trinitro- 
toluene is lower than this figure. 

When the alpha trinitrotoluene was isolated, it 
was the only one of the six that was known, and even 
had there been present considerable amounts of the 
beta, gamma, or other isomers, no means was at hand 
for identifying them, or for separating them from the 
alpha. It was under these conditions that the melting- 
point of the first trinitrotoluene was determined, and 
it seems to be a very evident fact that the melting- 
point as determined by the earlier chemists was not 
the melting-point of pure alpha trinitrotoluene, but 
was a melting-point of a mixture of the isomeric tri- 
nitrotoluenes. The melting-point as determined by 
recent investigators varies from 80.5 to 80.85° C. 
Comey gives a melting-point of 80.5 to 80.6. (1) 
Giua and Molinari state 80.65. (2) Rintoul's deter- 
mination gives 80.8 to 80.85. (3) These determina- 
tions are so close together that the mean of 80.65 
may be adopted without any serious error, even con- 
sidering the true melting-point to be at the lower or 
higher extreme. 



80 TRINITROTOLUENE 

The complete table of melting-points of the six 
trinitrotoluenes is : 

Alpha 80.65° C. 

Beta 112. 

Gamma 104 . 

Delta 137.5 

Epsilon 97.2 

Zeta 79.5 

Each of the trinitrotoluenes crystallizes in definite 
form. The forms of the first three have been deter- 
mined. No references are at hand, however, to show 
the crystalline structure of the last three isomers. 

Alpha trinitrotoluene crystallizes in long yellow 
needles, which belong to the monoclinic system and the 
prismatic class. 

Beta trinitrotoluene crystallizes in thin plates of a 
dazzling white color, belonging to the assymetric 
system. 

The crystalline form of the gamma isomer, when 
crystallized from acetone, is rhombohedral crystals, 
which possess sharp edges, and which belong to the 
brachypinacoidal class. 

The solubilities of the alpha, beta and gamma 
trinitrotoluenes are very much the same. There are 
slight variances, it is true, but these are so slight as 
to be of no account; for instance, all three isomers are 
very slightly soluble in cold water; slightly soluble 
in cold alcohol; and very soluble in ether, acetone, hot 
glacial acetic acid, etc. Alpha trinitrotoluene is very 
soluble in hot alcohol, while beta and gamma isomers 
are " moderately " soluble in the same substance. The 
specific solubilities of alpha trinitrotoluene are: 



PROPERTIES OF THE TRINITROTOLUENES 81 

Cold water, .021 per cent. 

Cold alcohol, 1.6 per cent. 

Hot alcohol, 10.0 per cent. 

Cold 100 per cent sulphuric acid, 6.6 per cent. 

Hot 100 per cent sulphuric acid, very soluble. 

Ether, toluene, acetone, ligroin, etc., very soluble. 

Preparation. The alpha TNT is prepared most 
easily by the direct nitration of toluene. There are, of 
course, varying amounts of the beta and gamma isomers 
formed. These may be removed from the alpha isomer 
by the means outlined under the preparation of the 
beta and gamma trinitrotoluene in the following para- 
graph. 

For the preparation of the beta and gamma trini- 
trotoluenes 100 parts concentrated nitric acid (which 
has been distilled from twice its weight of concentrated 
sulphuric acid) are placed in a flask. Two parts of 
meta mononitrotoluene are then added cautiously. 
After the first violent reaction is over, twenty-five parts 
of concentrated sulphuric acid are added with cooling. 
The mixture is then allowed to stand for twenty-four 
hours, being heated during this time to boiling. The 
boiling should not be violent, but should be rather quiet. 
Upon cooling the reaction mixture the beta and gamma 
trinitrotoluenes will separate out. The precipitated 
mass is well washed with hot water, and then dissolved 
in hot alcohol. Upon cooling, the gamma isomer crys- 
tallizes first, and thus a crude separation may be made 
in this fractional crystallization. To extract the 
beta isomer from the mixture it may be agitated with 
carbon bisulphide. The beta trinitrotoluene dissolves, 
while the gamma remains as a residue. Upon evapora- 



82 TRINITROTOLUENE 

ting off the carbon bisulphide, the beta TNT may be 
obtained in crystalline form. Both isomers may be 
further crystallized by dissolving in hot alcohol and 
cooling the solution slowly. The crystals thus formed 
are very compact and pure. Any alpha TNT may be 
separated from the other two isomers by fractional 
precipitation from alcohol, the alpha being slightly 
more soluble than the others. 

Chemical Properties. There are many well-known 
reactions in which the three first isomers participate. 
Some of these reactions are little better than theoretical, 
and for this reason will be omitted in this discussion. 
The object in describing the few reactions given is to 
include such reactions as may form a basis for the 
separation of the trinitrotoluenes, or which may be of 
interest to the manufacturer or user of TNT. 

The alpha, beta, and gamma trinitrotoluenes all 
react with aniline, giving distinctive products. The 
alpha trinitrotoluene compound with aniline is the 
product of an additive reaction only. This compound 
crystallizes in long glistening needles, dark violet in 
color, and has a melting-point of 83° C. The crys- 
tals themselves are the same physically as these formed 
when trinitrobenzene reacts with aniline, and therefore 
cannot be used as a means of differentiating between 
trinitrobenzene and trinitrotoluene. The reaction pro- 
ceeds according to the following equation: 

C 6 H 2 • CH 3 • (N0 2 ) 3 +C 6 H 5 • NH 2 

-» C 6 H 2 • CH 3 • (N0 2 ) 3 • C 6 H 5 • NH 2 . 

Beta and gamma trinitrotoluenes react with aniline, 
but the product formed is not an additive compound 



PROPERTIES OF THE TRINITROTOLUENES 83 

as in the case of alpha trinitrotoluene. Beta trinitro- 
toluene is rather indifferent to the presence of aniline 
at first. After a time the solution acquires a red color, 
and a vapor is given off. To accelerate the reaction, 
the mixture is heated in a sealed tube for four or five 
hours. During the heating a strong pressure develops 
in the tube. On opening the tube and removing the 
contents, it is found that two distinct substances are 
present : The first of these is a brownish fluid, and the 
other is a faintly crystalline mass which also has a 
brown color. Good crystals of the latter substance 
may be obtained by crystallizing from acetic acid, 
the solution being decolorized with animal charcoal and 
filtered before the crystallization is allowed to cool. 
Two crystallizations give a very pure substance, which 
crystallizes in short gold-colored needles, and which 
melts at 94° C. This substance is beta-nitroto- 
ludin. 

Gamma trinitrotoluene reacts with aniline readily 
in hot alcoholic solution. Boiling for several hours is 
necessary to carry the reaction to completion. Orange- 
colored crystals finally separate which are insoluble 
in cold alcohol. The first mother liquor from this 
crystallization reacts with hydrochloric acid giving a 
gas. Hepp states that this gas is very likely the result 
of the reaction of a diazo compound. The reactions 
by both the beta and gamma forms of trinitrotoluene 
and aniline are the same, but the beta form seems harder 
to start. The reaction may be represented by the fol- 
lowing equation : 

C 6 H 2 • CH 3 • (N0 2 ) 3 +3C 6 H 5 • NH 2 -> 
C 6 H 5 • N 2 • NH • C 6 H 5 +C 6 H 2 • CH 3 • (N0 2 ) 2 • NH • C 6 H 5 . 



84 TRINITROTOLUENE 

Dimethylaniline reacts with the three trinitrotolu- 
enes in the same manner as the aniline, the resulting 
products, of course, being dimethyl compounds. 

These reactions divide the three trinitrotoluenes 
into two distinct classes. Alpha trinitrotoluene con- 
stitutes the one class, in which one molecule of trini- 
trotoluene reacts with but one molecule of aniline or 
dimethylaniline while in the second class, one molecule 
of either the beta or gamma trinitrotoluenes reacts 
with three molecules of the base, forming decomposi- 
tion products instead of one addition product. The 
property of forming addition products seems to hinge 
upon the symmetrical positions of the nitro-groups. 

All three of the above mentioned trinitrotoluenes 
form compounds with the alkali hydroxides. As in 
the case of the aniline reactions, a distinct difference 
exists between the reaction of alpha trinitrotoluene 
and that of the beta and gamma isomers. The alpha 
isomer reacts with sodium hydroxide — two molecules 
of the former reacting with one of the latter — forming 
an unstable condensation product. Sodium salts of 
this product are very unstable, also, and are sometimes 
formed in the reaction: 

2C 6 H 2 • (N0 2 ) 3 • CH 3 +NaOH 

-> (N0 2 ) 3 • C 6 H 2 • CH 2 • CH 2 • C 6 H 2 (N0 2 ) 3 . 

The beta and gamma isomers react in the ratio of 
one molecule of the trinitrotoluene to one molecule of 
sodium hydroxide. Instead of the product being a 
condensation as with alpha trinitrotoluene; a deriva- 
tive of cresol is formed. The sodium salts of the dini- 
trocresols have much the same properties as the 



PROPERTIES OF THE TRINITROTOLUENES 85 

picrates, being very unstable. These reactions explain 
why the sodium compounds of TNT explode with such 
ease, and why care must be used in selecting the salt 
used in the washing of the crude product. The reac- 
tions of the beta and gamma isomers are, respectively: 

C 6 H 2 • (N0 2 ) 3 • CH$ +NaOH 

-> C 6 H 2 • (N0 2 ) 2 (2-4) • CH 3 • OH(3). 

C 6 H 2 • (N0 2 ) 3 • CH 3 -t-NaOH 

^C 6 H 2 (N0 2 ) 2 (2-4)CH 3 OH (5). 

It will be noted that in each of these reactions the 
nitro-group that is meta to another nitro- group and 
ortho or para to the methyl group does not react. 
This is exactly what would be expected from the orien- 
tationof the nitro-group, because the meta position to 
the methyl group is the unnatural position for the nitro- 
group, and with a basic substance such as NaOH it 
would be expected that it would be the one affected. 

Sodium hydroxide is not the only salt that will form 
these unstable compounds with the trinitrotoluenes. 
Hepp (4) found that even the carbonates of the alkalies 
gave precipitations of a dark brown substance on the 
solution being treated with acid. He filtered this 
mixture, and on extracting the residue with ether 
obtained " a small amount of an oil, which is probably 
a dinitrocresol." Later Hepp identified his substance, 
and proved conclusively that it was a dinitrocresol. 

Alpha trinitrotoluene reacts with naphthalene in 
benzol solution to form a needle like substance melting 
at 97 to 98° C. Beta trinitrotoluene and gamma 



86 TRINITROTOLUENE 

trinitrotoluene also react with naphthalene. Beta 
trinitrotoluene reacts rather difficultly, and the solu- 
tion must be hot, and not too concentrated. The 
gamma isomer reacts much easier than the beta, but 
not quite so easily as the alpha. (5) The analysis of 
of the three trinitrotoluene-naphthalene compounds 
proves them to be addition compounds. The sub- 
stance formed has the formula CeH2(N02)3 ■ CH3 • CioHg. 
The color of all the addition compounds of trinitrotolu- 
ene and naphthalene is yellowish-white. The melting- 
points are: Alpha, 97 to 98° C. ; beta, 100° C; gamma, 
88 to 89° C. 

Anthracene reacts with all of the trinitrotoluenes 
similarly to naphthalene, addition compounds being 
formed. 

A further reaction with sodium carbonate has been 
discovered by Will. (6) He has obtained a reaction 
between the beta and gamma isomers and 1 per cent 
sodium carbonate solution in which reaction dinitro- 
tolyloxides are formed. The salts of this compound 
are very explosive. 

The reactions of all six isomeric trinitrotoluenes with 
alcoholic ammonium sulphide are known. Aside from 
the compounds formed, the color of the solutions 
are different in each case, and form a very good 
method of determining which trinitrotoluene is 
present. 

Alpha trinitrotoluene gives a deep red color. 

Beta trinitrotoluene gives a greenish-yellow color. 

Gamma trinitrotoluene gives a blue color. 

Epsilon trinitrotoluene gives a rose red color. 

Zeta trinitrotoluene gives an orange color. 

This reaction, as described by Tiemann (7), pro- 



PROPERTIES OF THE TRINITROTOLUENES 87 

ceeds thus, to use Tiemann's words: " If trinitrotoluene 
(the alpha modification was used by Tiemann) is 
covered with strong alcoholic ammonium sulphide, 
a violent reaction takes place. The solution becomes 
first red, then seethes gently as the trinitrotoluene dis- 
solves. Soon a mixture of sulphur and small yellow 
crystals separate. Boiled down the mixture leaves a 
residue which in dilute hydrochloric acid gives a basic 
compound. This compound, when precipitated by 
ammonia and crystallized from water, forms small red 
prisms, melting at 132° C. These crystals cannot 
be sublimed without decomposition . . . Alcohol ex- 
tracts from the residue left by the hydrochloric acid 
treatment, a second compound, which, when freed from 
sulphur forms small yellow crystals. ... It is probable 
that the compounds formed are respectively nitro- 
diamidotoluol and dinitrotoluol." 

Sudborough (8) has succeeded in forming addition 
compounds with alpha and beta naphthylamine and 
alpha trinitrotoluene. These reactions take place 
at moderate temperatures in alcoholic solutions. 

Thiele and Escales (9) report that stilbene deriva- 
tives are formed by the reaction of alpha trinitrotoluene 
and either benzaldehyde or piperidine. The reactions 
probably proceed thus: 

C 6 H 2 • (N0 2 ) 3 ■ CH 3 + C C H 5 • CHO 

-> (N0 2 )3-C 6 H 2 -CH : CHC 6 H 5 . 

The reaction with piperidine will not form a true 
stilbene, but a hexahydroazostilbene. These reac- 
tions are important from a commercial standpoint, since 



88 TRINITROTOLUENE 

the stilbenes are the bases from which several im- 
portant dyes are made. 

Cohen and D akin, (10) investigating more thor- 
oughly the reaction discovered by Tiemann, to which 
reference is made above, identified the product from 
the reaction of ammonia and hydrogen sulphide on 
trinitrotoluene as dinitrotolylhydroxylamine. Dini- 
trotoluene also reacts similarly with this reagent. The 
trinitrotoluene reaction takes place thus: 

C 6 H 2 • CH 3 • (N0 2 ) 3 +H 2 S +NH4OH 

-> C 6 H 2 • CH 3 • (N0 2 ) 2 • NHOH. 

On oxidation trinitrotoluene yields trinitrobenzoic 
acid. These acids are important because Meyer's 
esterification law was established by the preparation 
of the symmetrical trinitrobenzoic acid. Until 1914, 
but one of the acids — the symmetrical — was known. 
In this year Giua discovered the second and third acids, 
which he prepared from the beta and gamma trinitro- 
toluenes. The trinitrobenzoic acids are named accord- 
ing to the trinitrotoluene from which they are 
prepared. 

Heating results in the ultimate decomposition of 
TNT. Verola (11) found, while conducting experi- 
ments to determine the vapor tension of TNT, that 
beginning at 160° C. a steady evolution of gas took 
place. He therefore investigated the behavior of the 
substance at varying temperatures, measuring the gas 
evolved. The quantity employed by Verola was 5 g. 
The temperatures investigated were 160°, 180°, 201°, 
and 217.5°. At 160° the TNT decomposed very slowly, 



PROPERTIES OF THE TRINITROTOLUENES 89 

and a very slight volume of gas was given off. At 180° 
the decomposition increased, 8 cu.mm. of gas resulting. 
The quantity of gas increased steadily until at 217.5° 
the volume of the gas was 200 cu.mm. per minute. 
Upon heating the TNT still higher, it was found that 
very rapid decomposition took place at 281 to 286°. 
Verola determined that the reaction was exothermic. 

As would be expected from the results obtained by 
Verola, the heating of TNT lowers the melting-point 
appreciably. Starting with TNT melting at 80.75° 
the results obtained by the same investigator summarize 
thus: 

5 hours heating at 180 gave M.P. of 78°. 
2\ hours heating at 201 gave M.P. of 77°. 
\ hour heating at 217.5 gave M.P. of 59°. 

Continuing his investigations at lower temperatures, 
in order to find at what temperature TNT began to 
decompose. Verola heated TNT very long periods 
at lower temperatures. 

100 hours heating at 130° had no effect. 
80 hours heating at 150° gave a M.P. of 80.25°. 
177 hours heating at 150° gave a M.P. of 79.9°. 

From these figures it is evident that TNT is quite 
stable at temperatures below 130° C. The decomposi- 
tion begins at 150°, being very slight at this tempera- 
ture, and increases rapidly with increased temperature, 
until at 281° the decomposition takes place with 
explosive violence. 

The reaction of the burning of TNT differs from the 



90 TRINITROTOLUENE 

reaction of explosion. The former reaction takes place 
thus: 

2C 6 H 2 • CH 3 • (N0 2 ) 3 +21 oxygen ->14C0 2 +5H 2 +3N 2 . 

In case the TNT is not supplied with a sufficient amount 
of oxygen, very little carbon dioxide will be formed. 
In most cases where TNT burns, the oxygen supply is 
insufficient, and carbon results from the combustion. 
When the first condition applies, the volume of the gases 
are 1200 liters from 1.6 kg. of TNT. 

The reaction according to which TNT explodes may 
be represented thus : 

2C 6 H 2 • CH 3 • (N0 2 ) 3 -» 12CO +5H 2 +3N 2 +2C 
or -> 12CO +2CH 4 +3N 2 +H 2 

according to the conditions under which the explosion 
takes place. 

C. E. Bichtel (12) has analyzed the gases from TNT 
under several conditions of explosion. From the com- 
plete explosion of the material under atmospheric 
pressure the gas gave the following analysis: 

Per Cent. 

Carbon monoxide 70.5 

Carbon dioxide 3.7 

Hydrogen 1.7 

Nitrogen 19.9 

Carbon 4.2 

Under pressure, the explosion of TNT gives a dif- 
ferent gas, including methane and considerably more 
hydrogen : 



PROPERTIES OF THE TRINITROTOLUENES 91 

Per Cent. 

Carbon monoxide 59.01 

Carbon dioxide 1 . 93 

Methane 1.97 

Hydrogen 21 .05 

Nitrogen 16 . 05 

The gases from the explosion of TNT in a lead block 
(from Trauzl test) upon partial analysis gave these 
figures : 

Per Cent. 

Carbon dioxide 20 . 60 

Carbon monoxide 46 . 02 

Methane 1.40 

Hydrogen 7.61 

Hydrocarbons 1 . 08 

Some authorities state that in all probability gases 
of entirely different constitution exist at the moment of 
detonation than after being cooled for analysis. The 
formation of methane and carbon dioxide may be 
due to the heat of the gases at the moment succeeding 
the explosion, at which moment the gases may, due to 
the heat, be dissociated. As the gas cools, these 
atoms recombine, but not in their original compounds. 

The effect of daylight on TNT is very marked. 
A sample of light cream TNT darkens to a deep brown 
on exposure to strong sunlight for a few hours. This 
action is, in reality, a slight decomposition. Just 
what the products of this decomposition are, is not 
definitely known, but they may be separated from the 
TNT itself by solution in acetone. (13) 

Experiments to determine the sensitiveness of TNT 
to shock have been carried out by von Schrotter. (14) 



92 



TRINITROTOLUENE 



In his report, he tabulates the results and compares 
TNT to several other explosives: 







Maximum 










Height at 










which no 


Rate of 


Gas. 

Vol. 

(L. per 

Kg.) 


Explosive. 


Density. 


Explosion 
Occurs when 


Detona- 
tion. 






a 2-kg. wt. 


(M per 






Drops on .1 


Sec.) 






g. of Explo- 










sive. 






Dry guncotton . 


1 . 22 (compressed) 


5 cm. 


6383 


887 


Wet guncotton . 


1 . 35 (compressed 


40 


5230 


901.7 


Picric acid 


.85 (crystals) 








Picric acid 


1.62 (cast) 


20 


8183 


768 




1 . 48 (compressed) 








Trinitrotoluene 


.90 (crystals) 








Trinitrotoluene 


1 . 55 (cast) 


80 


7620 


800 


Trinitrotoluene 


1 . 62 (cast under press) 








Trinitrotoluene 


1 . 60 (compressed) 









Von Schrotter also experimented upon the detona- 
tion of one charge of TNT by the explosion of another 
charge. In this work charges of 2 kgs. were used, which 
were enclosed in hollow metallic shells. One of these 
shells was equipped with an electrically fired detonator, 
and the second shell was placed a certain distance from 
the first. It was found that the TNT detonated ten 
times out of ten attempts at 110 cm. A heap of un- 
confined TNT detonated at a distance of 7.5 cm. from 
the prime charge. 

A mixture of TNT and other substances that may 
be detonated by heat alone is described by Goettig. (15) 
The analysis of Goettig's mixture shows it to consist 
of: Barium nitrate, 9.83 per cent; TNT, 22.22 per 
cent; nitrocellulose, 67.96 per cent. The detonation 
of this mass may be most easily effected by an elec- 
trically heated platinum wire. 



PROPERTIES OF THE TRINITROTOLUENES 93 

Giua has studied the physical properties of mix- 
tures of the dinitrotoluenes and the trinitrotoluenes. 
He found that eutectics were formed in the ratio of 
three molecules of the lower nitration product to two 
of the higher. Langenscheidt (16) has determined 
the melting-points of a mixture of symmetrical trinitro- 
and alpha dinitrotoluenes in varying proportions. His 
results differ from Giua, because they indicate that the 
eutectic is formed in the ratio of one molecule of the 
lower to one molecule of the higher melting-point. 



Per Cent 
DNT. 


Per Cent 
TNT. 


M.P. 


100 





69.5 


90 


10 


65.5 


80 


20 


60.3 


70 


30 


52.8 


60 


40 


48.0 


50 


50 


46.0 


40 


60 


51.5 


30 


70 


59.0 


20 


80 


67.0 


15 


85 


70.0 


14 


86 


71.8 


13 


87 


72.0 


12 


88 


73.0 


11 


89 


73.5 


10 


90 


73.2 


9 


91 


74.8 


8 


92 


75.0 


7 


93 


75.6 


6 


94 


76.3 


5 


95 


77.0 


4 


96 


77.7 


3 


97 


78.3 


2 


98 


79.0 


1 


99 


79.5 





100 


80.4 



94 



TRINITROTOLUENE 



The density of TNT varies directly with the pressure 
applied. The following table shows the density at 
various pressures (17): 



Pressure, Atm. 


Density. 


250 


1.32 


500 


1.38 


1000 


1.48 


1500 


1.54 


2000 


1.57 


2500 


1.59 


3000 


1.61 


3500 


1.615 



CHAPTER VIII 

PROPERTIES OF THE MONO- AND DINITRO- 
TOLUENES 

The Mononitrotoluenes. There are three isomeric 
mononitrotoluenes. The structural formulae of these 
are: 

CH 3 CH 3 CH 3 




Ortho Meta 



Para 

Jno, 

NO 



The melting-points of two of the mononitrotol- 
uenes, like that of the alpha trinitrotoluene, have been 
under discussion for some time. Astromisslewsky (1) 
has made an extended study of the ortho mononitro- 
toluene to find out why this modification exhibits what 
seems to be a double melting-point, which fact had been 
noted by many preceding investigators. Astromis- 
slewsky's results proved that this mononitrotoluene 
exists in two forms. One of these forms was designated 
as the alpha or " labile " modification. The melting- 
point of this modification was determined to be 
-10.56° C. To the second form Astromisslewsky 
gave the name of Beta or " stable " modification, 
having a melting-point of -4.14° C. The alpha form 
seems to go over spontaneously to the Beta modifica- 

95 



96 



TRINITROTOLUENE 



tion. Extended research indicates that the transi- 
tion point is close to the melting-point of the alpha 
form. 

Rintoul (2) has determined the correct melting-point 
for para mononitrotoluene. After much trouble in puri- 
fication and separation from the accompanying ortho 
and meta forms, he finally determined the correct 
melting-point to be 51.6° C. and not 54° C. as was pre- 
viously supposed. 

The corrected boiling- and melting-points of the 
mononitrotoluenes are : 





Boiling-point. 
° C. 


Melting-point. 
°C. 


Ortho 

Meta 

Para 


223.3 
230.0 
237.0 


-10.56 (-4.14) 
16.0 
51.6 



Specific gravities: 



Ortho 1.168 (15 deg.) 

Meta 1.168 (22 deg.) 

Para 1.123 (54 deg.) 



Crystalline Form: The crystalline form of the ortho 
nitrotoluene has evidently not been thoroughly in- 
vestigated, since the various chemists do not agree 
upon this point. This is possibly due to the presence 
of both the alpha and the beta forms in the mixture. 

Meta nitrotoluene crystallizes in monoclinic prisms, 
and para nitrotoluene crystals belong to the trimetric 
system. 

Preparation. The preparation of the ortho nitro- 
toluene is most easily carried out by the nitration of 



MONO- AND DINITROTOLUENES 97 

toluene. A very good mixture for this purpose is 
180 parts of toluene to a mixture of 315 parts concen- 
trated sulphuric acid (sp.gr. 1.84) and 200 parts con- 
centrated nitric acid (sp.gr. 1.44). The toluene is 
placed in a vessel of suitable size and shape that is 
equipped with a motor-driven stirrer, and the acid 
mixture is added slowly. The temperature of the reac- 
tion mixture should not rise above 30° C. The mix- 
ture of nitrotoluenes from this nitration consists of all 
three isomers, with the ortho greatly predominating. 
The separation of the three isomers may be made by 
repeated fractional distillation, provided the nitration 
has been carried out at a temperature below 30°. If 
the temperature has risen above this point, there is 
danger that some dinitrotoluene or even trinitrotoluene 
has been formed, and upon distilling the mixture may 
explode. 

A possibly better method of separating the isomeric 
mononitrotoluenes is one used by the firm of Meister, 
Lucius & Bruning. This consists in cooling the 
mixed nitrotoluenes to —4 to —10 °, and removing 
the liquid portion after about one-half the mixture has 
crystallized. The separation may be effected by a 
centrifuge. The liquid obtained by one crystalliza- 
tion is practically pure ortho nitrotoluene. The result- 
ing mixture of meta and para nitrotoluenes may be 
separated by steam distillation. The para is very 
volatile with steam, while the meta is but slightly so. 

A considerable amount of para nitrotoluene may be 
separated from the above residue, and easily enough 
so that further methods of preparation would be super- 
fluous. A very small amount of the meta nitrotoluene 
is present, also, but this amount is too small to be of 



98 TRINITROTOLUENE 

any value. A much better method of preparing the 
meta isomer is by the successive acetylization, nitra- 
tion, saponification, diazotization, and finally boiling 
with alcohol, of ortho- or para-toluidin. The amino 
group is present and thus prevents the nitro-group 
entering in its regulation position. Acetylization both 
protects the amino group, and also renders it sus- 
ceptible to diazotization, which procedure is necessary 
for the removal of the amino group after the meta 
nitro-compound has been formed. The reactions in 
these various stages take place thus: 

CH 3 • C 6 H 4 • NH 2 + CI • OC • CH 3 

-> CH 3 • C 6 H 4 • NH • OC • CH 3 +HC1 ; 

CH 3 • CoH 4 • NH • OC • CH 3 +HON0 2 

->CH 3 C 6 H 3 N0 2 NHOCCH 3 +H 2 0; 

CH 3 • C 6 H 3 • N0 2 • NH • OC ■ CH 3 +HCl(Aq) 

-> CH 3 • C 6 H 3 • N0 2 • NH 2 • HC1 +CH 3 COOH ; 

CH 3 • C 6 H 3 • N0 2 • NH 2 • HC1 +HONO 

->CH 3 C 6 H 3 N0 2 N : NC1+2H 2 0; 

CH 3 C 6 H 3 N0 2 N : NC1+H0C 2 H 5 

-> CH 3 C e H 4 • N0 2 +N 2 +C 2 H 4 0. 

Chemical Properties. On oxidation, the mono- 
nitrotoluenes are all converted to the corresponding 
nitro-benzoic acid. This oxidation can best be carried 



MONO- AND DINITROTOLUENES 99 

out by boiling for a long time with an alkaline solution 
of potassium ferricyanide. 

Upon reduction, the mononitrotoluenes act differ- 
ently, according to the metal used in the reduction. 
Ii iron be used with hydrochloric acid, the correspond- 
ing toluidin is produced, the reaction being analogous 
to the preparation of aniline. If zinc and hydrochloric 
acid is employed, a chlortoluidin is produced. 

The reduction of the mononitrotoluenes to toluidins 
by the use of iron and hydrochloric acid forms the basis 
for a method of estimation of the para isomer in crude 
nitrotoluene. (3) A weighed amount of the mixed 
toluidins is dissolved in ether, and then ethereal oxalic 
acid is added. The toluidins all form compounds with 
oxalic acid, and all but the para compound are soluble 
in ether. The solution is then filtered, the residue 
washed with ether, then dissolved in water and titrated 
with N/10 sodium hydroxide, using phenolphthalein 
as the indicator. 

The sulphonation of the mononitrotoluenes offers 
a qualitative test for ortho nitrotoluene, in that the 
sulphonation product of this isomer gives no red color 
when boiled with sodium hydroxide. 

Green, Davies and Horsfall (4) have investigated 
the products formed when sodium hydroxide acts upon 
the nitrotoluenes, especially the para isomer. They 
have found that the first product of the reaction 
is a dinitrosodistilbene, which then condenses to a 
dinitroazodistilbene, having the following composition: 

N0 2 C 6 H 4 CH:CHC 6 H4N:N-C 6 H 4 -CH:CH-C6H4-N02 
The reaction may also go to dinitrodibenzyl, accord- 



100 TRINITROTOLUENE 

ing to the temperature of the reaction and the oxidiz- 
ing conditions, the formula being: 

N0 2 • C 6 H 4 • CH 2 • CH 2 • C 6 H 4 • N0 2 

(nitro-groups in position 4-4). 

If the reaction be started cold, and gradually heated up, 
the product resulting is a dinitrostilbene : 

N0 2 C 6 H 4 CH : CHC 6 H 4 N0 2 

(nitro-groups in position 4-4). 

The action of light on the mononitrotoluenes was 
investigated by Ciamician and Silber. (5) Their pro- 
cedure involved the solution of the nitrotoluene in 
alcohol. With this solution, it was found that light 
transformed the nitrotoluenes into the corresponding 
methyl quinaldine and the toluidin. This indicated 
that light has a pronounced reducing action on the 
nitrotoluenes, reducing the nitro-group to an amino 
group. 

The mononitrotoluenes form addition products with 
the inorganic salts. This property differs from the 
trinitrotoluenes, which form their addition products 
mostly with organic compounds. Walker and Spencer 
(6) have produced an aluminium chloride compound 
of mononitrotoluene, and Mascarelli (7) isolated an 
addition compound of para nitrotoluene and mercuric 
chloride,which had the formula NO2 • CeH 4 • CH3 • HgCl2. 
This substance separates from alcohol in pale yellow 
needles. Upon being heated, it softens at 105°, begins 
to melt at 150° and blackens at 222°. The properties 
of these compounds indicate that they are unstable. 



MONO- AND DINITROTOLUENES 101 

An interesting application of the color reaction of 
nitrotoluene with sodium hydroxide is made in detect- 
ing traces of nitrotoluene in nitrobenzene. The latter 
substance will not give a red color with sodium hydrox- 
ide, and by standardizing the colors, the test may be 
made roughly quantitative. This reaction may, of 
course, be applied to the detection of toluene in benzene 
by first nitrating. (8) 

Coparisow, in considering the results obtained 
by many investigators on the reactions of para 
mononitrotoluene reaches the following conclu- 
sions: (9) 

The reactive sensitiveness of nitro-groups toward 
alkalies increases with the increase of the nitro-groups 
in the molecule. 

The sensitiveness and number of chemical changes 
is greatly augmented by the presence of an alkyl 
radical in the para position, facilitating, probably, the 
formation of nitric esters. (R- NO (OH) 2). 

The reactivity of the molecule is very much in- 
creased by the introduction of electronegative groups 
in the ortho position to the alkyl radical. 

Alkalies produce addition, substitution, and con- 
densation products. Alkalies and alkali compounds 
produce red colorations with alpha trinitrotoluene. 
Coparisow found that when 5 c.c. of a saturated solu- 
tion of potassium hydroxide in methyl alcohol, cooled 
in solid carbon-dioxide-ether mixture, are added to 
.166 g. of pure symmetrical trinitrotoluene, dissolved 
in a mixture of 1 c.c. pryidine and 5 c.c. methyl alcohol; 
the latter solution being kept cool in solid carbon- 
dioxide-ether mixture, the color change took place at a 
temperature as low as — 65° C. 



102 



TRINITROTOLUENE 



The Dinitrotoluenes. The structural formulae of 
the six dinitrotoluenes are as follows : 



Alpha 



Gamma 



CH 3 

/Vo, 



N0 2 
CH 3 



\/ J 



Beta 



2 N 



Delta 



CH 3 
/% 

I I 

CH 3 

^Nno, 



2 N 



\/ 



Epsilon 



CH 3 

2 N // ^N0 2 



\f 



Zeta 



CH 3 



NOs 



N0 2 



Melting-points: 

Alpha 70° C. 

Beta 93 

Gamma 63 

Delta 48 

Epsilon 61 

Zeta 60 



Crystalline form: 
Alpha, monoclinic needles, yellow in color. 
Beta, yellow needles from a mixture of acetic acid and 

benzol. 
Gamma, hair-like needles when crystallized from dilute 

acetic acid. 



MONO- AND DINITROTOLUENES 103 

Delta, yellow needles from ligroin. 
Epsilon, yellow needles from alcohol. 
Zeta, very long needles when crystallized from carbon 
disulphide. 

Preparation. The alpha dinitrotoluene is obtained 
usually by the nitration of mononitrotoluene. It may 
also be prepared by eliminating the amino group from 
nitrotoluidin, first diazotizing, then forming the hydro- 
chloride and saponifying. 

The beta isomer is formed by eliminating the amino 
group from dinitro-ortho-toluidin, as outlined above. 

The gamma dinitrotoluene may be easiest pre- 
pared by heating 2-3-1-4 dinitrotoluic acid with dilute 
hydrochloric acid. The reaction goes in two steps :(10) 

(1) CH3-C 6 Ho.(N0 2 )2-COOH+HCl(aq) 

-►CHs-CeHa-CNOaVCOCl; 

(2) CH 3 C 6 H 2 -(N0 2 ) 2 COCl+KOH 

-> CH 3 • C 6 H 3 • (N0 2 ) 2 +KC1 +H 2 0. 

The delta modification may be formed from 1-4-3-6 
dinitrotoluic acid as in the case of the gamma isomer. 
Delta dinitrotoluene may also be formed by inter- 
action of toluquinone dioxime and nitric acid. (11) 

Epsilon dinitrotoluene is formed to a slight extent 
when mononitrotoluene is further nitrated. It may 
also be formed in the pure state by the elimination of 
the amino group fromd initro-para-toluidin. 

Zeta dinitrotoluene is prepared from the nitration 
products of toluene. 

Chemical Properties. The chemical properties of 
the dinitrotoluenes have not been investigated nearly 



104 TRINITROTOLUENE 

as thoroughly as have those of the mononitrotoluenes 
and the trinitroluenes. This is possibly because the 
dinitrotoluenes are merely an intermediate between the 
mono- and trinitrotoluenes, and are important only as 
such. While it is true that in some plants the dinitro- 
compound forms the starting point for TNT, yet in 
the vast majority of factories the raw material is 
either toluene or mononitrotoluene. 

The alpha dinitrotoluene will form addition prod- 
ucts with naphthalene and anthracene just as the alpha 
trinitrotoluene will do. The naphthalene product has 
the following formula. (12) 

C 6 H3-(N0 2 )2-CH3-CioH8. 

This same DNT may be reduced by iron and aqueous 
hydrochloric acid to tolylene m-diamine. Ammonium 
monosulphide partially reduces alpha dinitrotoluene 
in which reduction the para group is the one concerned. 
Stannous chloride and alcohol exert the same action. 
The product in each case is C6H3CH3NO2NH2. 

Beta dinitrotoluene upon oxidation with ferricyanide 
forms the corresponding dinitrobenzoic acid. 

Some work has been done on the reduction of the 
alpha and epsilon dinitrotoluenes by electrochemical 
means. Brand and Loller (13) have prepared from the 
epsilon compound a 2-2-dinitro-6-6-azoxytoluene and a 
2-2-dinitro-3-hydroxy-6-6-azotoluene. The formation is 
determined by the solution used. The alpha dinitro- 
toluene gives similar substances. 

The Omega Nitrotoluenes (Phenylnitromethanes). 
Under various circumstances in the regulation manu- 
facture of TNT a side-chain nitrated compound is 



MONO- AND DINITROTOLUENES 105 

formed. These constitute the class of nitrotoluenes 
known as the omega class. The first reference to the 
preparation of one of these compoundsis made by 
Holleman (14) in 1894, when he prepared an " exoni- 
trotoluene." Hantszch (15) and Ponzio (16) have done 
considerable work on the properties of the omega nitro- 
toluenes. The results of both these investigators 
indicate that these nitro-compounds are very unstable. 
Ponzio prepared the phenyldinitromethane, which 
crystallized in large prisms. The crystals melted at 
79° C, and upon heating were found to decompose vio- 
lently at 130° or above. The products of the decom- 
position of phenyldinitromethane are " red vapors and 
benzaldehyde." The same man prepared the potas- 
sium derivative of the above-mentioned compound, 
and found it to be less stable than the phenyldinitro- 
methane itself. In fact, the alkali derivative exploded 
when " slightly heated." 

According to Neogi and Adhicary (17) omega 
mononitrotoluene is readily prepared by the action of 
mercurous nitrate or benzyl chloride. Heim (18) con- 
cludes from a series of researches, that pure phenylnitro- 
me thane is not subject to spontaneous decomposition, 
but a small amount of impurities may cause such 
action. Korwalloff (19) has determined that this sub- 
stance, on reduction, yields the corresponding aldehyde 
and oxime. 



CHAPTER IX 

ACCIDENTS 

TNT is considered the safest explosive that has ever 
found a wide application in warfare. The manufacture 
of this explosive is also comparatively safe, as long as 
it is carried out with ordinary caution. There is no 
doubt but that in the present rush to produce TNT in 
the greatest possible quantities, and in the least pos- 
sible time, there is a tendency to be somewhat lax in 
the enforcing of precautionary measures, and that there 
is also a tendency to disregard the chemical properties 
of the various products and by-products that result from 
the manufacture of this product. The fact that TNT 
is primarily an explosive, makes certain the further fact 
that there are certain conditions under which it must 
explode. It is true that not many of these conditions 
are known, but it certainly is not impossible that some 
of these conditions can be produced in the plant where 
the explosive is manufactured. It is no more impos- 
sible that TNT will explode under conditions concern- 
ing which we know nothing. These conditions may 
just as well be brought about as the first kind. To be 
on the safe side, then, it is up to the superintendent 
of a plant to be certain that no conditions exist in his 
plant but those under which it is definitely known that 
TNT will not explode. This will insure the safety of 
the men, and the safety of the plant. 

106 



ACCIDENTS IN TNT PLANTS 107 

Previous to 1914, there were in all less than a half- 
dozen accidents reported in TNT plants. Within 
the last year there have been not less than twenty 
explosions and accidents in the United States alone. 
It is true that not all of these have been due to the 
detonation of TNT, but probably every one has been 
due to carelessness on some employee's part. With con- 
ditions as existed previous to the war, the manufacture 
of TNT could be carried out with as great care as was 
thought necessary, but with the total rearrangement 
of conditions as they exist to-day, there is no doubt 
but that in many cases certain details which, although 
minor in nature, are really important, are not given the 
attention they require. 

The pre-war accidents in which TNT was concerned 
were due in some cases, at least, to the action of some 
substance other than the TNT. For instance: In 
1909 an explosion occurred in the crystallizing room of a 
TNT plant at Schoenbeck, Germany, in a long rotating 
drum which was used for drying TNT crystals. In this 
particular plant centrifuges were used to separate the 
crystals from the alcohol used for the recrystallization. 
It is thought that a hot bearing may have ignited the 
alcohol vapors in the room, thus causing the explosion. 
Experts differ on the subject. Some believe that the 
explosion was due only to a mixture of air and alcohol 
vapor, while others think that TNT dust was added to 
the explosive mixture. In either case, the TNT did 
not explode, since it was found that after the fire, 
following the explosion, was extinguished, there re- 
mained some unburned TNT in the drum. Further- 
more, a wood sieve containing several hundred pounds 
of TNT was burned, but the TNT did not explode. 



108 TRINITROTOLUENE 

A metallic container filled with TNT was blown 300 
yards, but the explosive was only slightly melted on the 
top. Another explosion took place in 1906 in the 
storeroom of the Roberite factory situated at Witten. 
The room was filled with TNT and ammonium nitrate. 
Forty-two persons were injured in this explosion. 

Both of the above cases show that the explosions 
were not due to the detonation of TNT alone, but to 
the combined action of the TNT and some other sub- 
stance. 

Two further accidents are interesting, although not 
much is known concerning the conditions surrounding 
the explosions. In 1908 an explosion of TNT at the 
factory of Letsch & Co., Huddersfield, caused the death 
of five men. Another explosion in the washing plant 
of a German factory in 1912 resulted in the death of 
four men. 

Even considering the high casualty rate of the pres- 
ent, the explosives manufacture has a lower injury 
and death rate than has railroading. Dr. W. G. 
Hudson, the medical director of the E. I. Dupont 
deNemours Co., " hit the nail on the head " in his 
recent paper on " Safeguards in the Manufacture 
of Explosives" when he said: " If explosives like 
dynamite, smokeless powder and TNT were made 
only by skilled chemists, under the best of laboratory 
conditions, they would seldom, if ever, cause explosion 
accidents. They are stable and safe explosives, and will 
stand a far greater degree of rough handling than the 
uninitiated have any idea of. But when such sub- 
stances have to be produced in the immense quantities 
required by present conditions, ordinary labor must 
be used, and many of these men are unskilled and have 



ACCIDENTS IN TNT PLANTS 109 

no speaking knowledge of English. However careful 
our chemists, supervisors and foremen may be, it is 
difficult indeed to guard against some one of these thou- 
sands becoming careless or negligent at times, and, 
of course, the results of an explosion are visited upon 
all in the vicinity." 

The problem of eliminating the explosive accidents 
becomes then, one of making the plant fool-proof, or of 
educating the foreigner. The first is impossible from 
the very nature of the work. A foreigner — and even 
some Americans — may be told repeatedly to keep away 
from any source of nitrous fumes, for instance, but 
sooner or later the effect of the most stringent warning 
wears off. The psychology of the employee of the 
explosive plant is another important factor in safety 
work. The ordinary workman knows full well that he 
is employed in an explosive plant, and that his work is 
dangerous because an explosion may occur. There- 
fore at the slightest unusual noise, or at the most 
trivial occurrence which is out of the ordinary, he 
immediately suspects trouble, becomes frightened, 
loses his head, and often turns an absolutely harmless 
situation into a dangerous one. To cite an example: 
The chemical engineer of a certain explosive plant 
was one day inspecting the installation of some acid 
eggs that were placed in a concrete pit. He noticed 
that the compressed air inlet valve leaked, thus allow- 
ing air to enter the egg, forcing the acid out through 
the discharge pipe which had, for some reason, been 
disconnected about 2 feet from the egg. A drop of the 
acid had struck him in the face, and while wiping it 
off with his handkerchief, he called to a nearby work- 
man to shut off the compressed air valve more tightly. 



110 TRINITROTOLUENE 

The workman, immediately saw a sign of an accident, 
became confused, and instead of turning off the air, 
opened the valve wide, forcing the acid charge out of 
the egg, and down on the man in the pit, burning him 
very badly. 

The plant officials are thus confronted with the great 
problem of educating the workmen to keep a level 
head at all times. 

Aside from accidents of the above nature, there are 
others the direct cause of which is carelessness on the 
part of foremen or superintendents, who are either 
ignorant of certain properties of their products, or who 
are negligent in the performance of their duties. One 
accident, due to a combination of these shortcomings, 
resulted from the too rapid mixing of spent acid from 
one stage of a nitration with fresh nitric acid to prepare 
the acid for the next nitration. Nitric acid on being 
mixed with spent acid, tends to form a separate layer 
apart from the spent acid unless it is thoroughly agi- 
tated. In this instance, the two-layer system formed, 
consequently the organic matter in the spent acid 
next to the layer of nitric acid was subjected to the 
nitrating action of the latter. As the reaction pro- 
ceeded, the mixture became warm, the heat in turn 
accelerated the nitrating reaction and so on. With 
such an uncontrolled reaction taking place an ex- 
plosion resulted. Nine times out of ten, the mixing 
of the nitric acid with the spent acid may be carried 
out without special precaution. The tenth time may 
be the cause of an explosion. In this particular plant 
the fortifying acid is always mixed in a particular man- 
ner. The explosion taught a lesson in the effects of 
disregarding minor details, and also concerning the 



ACCIDENTS IN TNT PLANTS 111 

properties of spent acid, which should have been 
determined before in the laboratory. 

There is surely no step in the manufacture of TNT 
which is entirely free from danger. Every step in 
the process should receive the utmost attention, and 
minor details should be worked out with the same 
care as the greater problems, rather than to " take a 
chance " that no accident will result. 



CHAPTER X 
TNT DISEASES 

The problem of disease incident to the manufacture 
of TNT has assumed great proportions in the last few 
years. Before the manufacture of TNT grew so large, 
an occasional sickness or death from poisoning caused 
no great comment. Now, however, with the many 
plants manufacturing this material, the number of 
men and women who are constantly becoming afflicted 
with diseases of various natures has grown to such a 
large figure that many physicians are devoting their 
entire time to the conquering of TNT diseases. 

To give some idea of the large number of persons who 
are affected in one way or another, the following figures 
are cited: Dr. Hamilton, in May, 1916, reported 703 
cases of TNT poisoning, and 33 deaths resulting from 
such poisoning. The Royal Society report of the same 
year gives 181 cases of jaundice alone, which were 
caused by TNT. The same report shows 52 deaths. 

There has been considerable discussion among some 
plant officials as to why the medical fraternity is unable 
to check the TNT disease. I have followed quite 
closely much of the research work that has been done 
on this problem, and I am of the opinion that the 
physicians are doing everything in their power to obtain 
sufficient knowledge concerning the action of TNT so 
they can, with the results obtained, lay the foundation 

112 



TNT DISEASES 113 

for the treatment of disease resulting from the action 
of TNT on the human body. When the recentness of 
these diseases is considered ; and when the vast amount 
of work necessary to be carried out with such diseases 
as tuberculosis, cancer, pneumonia and others, is con- 
sidered, it seems that the medical profession is to be 
congratulated for having progressed as far as they have 
in the understanding of this sickness. 

Many well-known physicians and pathologists have 
worked on this subject. Drs. More, Panton, Feldman 
and others have, by their researches, thrown much 
light on the action of TNT in the body. At the present 
time Dr. Samuel Haythorn, of the Singer Memorial 
Laboratory, Allegheny General Hospital, is engaged 
in a very extended series of researches to determine 
the various ways in which TNT gains an entrance 
into the body, and also to find out the effect of the TNT 
on the various tissues and organs in the body. The 
different ways in which TNT gets into the system has 
been investigated by Dr. More, who reaches the con- 
clusion that the most important means of entrance is 
through the skin, by actual contact with the material. 
In order to determine whether or not TNT has gone 
through the system, use is made of Webster's test 
which detects TNT, or possibly some product of its 
action in the body, in the urine. Webster's test is 
performed by placing 12| c.c. urine in a test tube, and 
mixing with an equal amount of 20 per cent sulphuric 
acid. The acidified urine is then extracted with ether, 
the extraction being carried out most easily in a separa- 
tory funnel, using 10 c.c. ether. The aqueous layer 
is drawn off, and the ether is washed with water and 
again separated. Five c.c. of the ether extract is 



114 TRINITROTOLUENE 

then mixed with 10 c.c. of a 4 per cent solution of potas- 
sium hydroxide in absolute alcohol. If TNT (or its 
product) is present, a pink color appears, which quickly 
changes to a purple and finally to a brown. The 
question as to whether Webster's test detects TNT or 
one of the products produced by the action of TNT 
upon the system has never been definitely settled. 

Dr. More has experimented upon the possibility of 
TNT entering the body through the skin, by rubbing 
some of the substance upon his hand, then washing 
immediately. He reports that he obtained a positive 
Webster's test on his urine for a period of ten days. 
Dr. Haythorn has been unable to verify More's work, 
in that he has been unable to secure a positive Webster's 
test on his urine at all by applying TNT externally . Fur- 
thermore, Haythorn allowed the TNT to remain in 
contact with the skin for a considerable period of time 
but was still not able to obtain a positive Webster 
reaction. Guinea pigs whose skin had been rubbed 
with TNT soon developed an eruption, at first not 
serious, but which soon became covered with crusts. 

Hay thorn's next experiment consisted in subject- 
ing rabbits and guinea pigs to the fumes of heated 
TNT for several hours a day for over a month. In 
this way the animals were under the same conditions as 
men in the plants who are forced to breathe fumes from 
washing or crystallizing apparatus, or from any source 
where the TNT is subjected to heat. The animals used 
in this test showed no Webster reaction. 

Haythorn then attempted to introduce TNT by 
feeding the animals milk which contained dissolved 
TNT. The animals rapidly lost weight, became list- 
less and soon died, one of them in three days. The 



TNT DISEASES 115 

urine of these animals showed a strong positive Web- 
ster's test. The liver, spleen and kidneys of one of 
these animals were very dark in color, due to the break- 
ing up of the red blood cells, and the deposition of 
the coloring matter in these organs. 

From Dr. Hay thorn's experiments, it seems that 
the greatest danger from TNT poisoning comes from 
actually swallowing the material. More does not 
agree with this. The effect of the TNT in the body 
seems to be mostly on the liver, the poison almost 
totally destroying the cellular portion of this organ. 

Several blood tests on patients afflicted with TNT 
poisoning shows that the substance in many cases 
attacks the red blood corpuscles, depositing the coloring 
matter of these corpuscles in the various organs such as 
spleen and kidneys. 

The differences in the results obtained by the work 
done by More and Haythorn, together with the fact 
that in some plants TNT poisoning is quite prevalent, 
while in others it is practically nil, has suggested that 
the poisonous effects may not be due to TNT itself, 
but to a phenylnitromethane; that is, a toluene ni- 
trated in the side chain. It is known that these phen- 
ylnitromethanes are very poisonous. It is also known 
that in some cases these compounds are formed dur- 
ing the nitration of toluene; for instance, if the nitric 
acid concentration of the acid mixture becomes very 
low, or if the temperature rises very high. In this way, 
some samples of TNT may contain the toxic phenyl- 
nitromethanes, while other samples may be free from 
them. This would explain the difference in toxic 
effect of the various TNT samples, and the variation 
in results obtained. 



116 TRINITROTOLUENE 

There are six definite forms of TNT poisoning 
known : 

1. Dermatitis, or eruption of the skin. Often called 
it j;nT rash." This form of poisoning is caused by- 
contact with the TNT, and may usually be cured by 
removing the cause. 

2. Gassing. This condition is due more to the in- 
halation of the nitrous fumes which occur during the 
nitration of TNT than to the TNT itself. The wind 
passages and lungs are often badly inflamed. Many 
cases develop into pneumonia, while others recover 
after a day or two of complete rest. In any case the 
patient who has been " gassed " should be given atten- 
tion by a physician. Ordinary first-aid methods, such 
as doses of dilute chloroform-alcohol mixtures, are 
not sufficient. 

3. Minor poisonings, which result from the handling 
of TNT or receptacles which are covered with the sub- 
stance. The effects differ from TNT dermatitis in 
that the effects are internal as well as external. The 
symptoms are dizziness, headache and sometimes 
nausea. Men or women who are new to the work, 
and whoare not accustomed to being a round TNT, are 
especially subject to this form of poisoning from TNT. 
The symptoms usually disappear after the person 
becomes more accustomed to the presence of TNT. 
Cases have been known, however, where the poison- 
ing has developed into a more serious form. 

4. Severe Poisonings. After the symptoms of a 
minor poisoning are displayed, there is a period in 
which the subject feels perfectly well, no effects of 
the TNT being noticeable. This neutral period may, 
in cases of extreme susceptibility, terminate in severe 



TNT DISEASES 117 

poisonings. The symptoms of the more severe cases 
being loss of appetite, vomiting and constipation. 
The severe poisonings from TNT appear to be the result 
of a cumulative action of the poison. 

5. Toxic Jaundice. This is the most serious form 
of TNT poisoning. It does not appear until at least 
six weeks after the exposure to the explosive. Some 
persons appear to be quite susceptible to the more 
serious forms of TNT poisoning, while others never 
feel anything other than the minor effects that are 
experienced upon the first exposure. There is yet a 
third class who are not affected in any way by TNT. 
Personally, I have often handled TNT until my hands 
and forearms were stained a deep golden brown, and 
have worked in an atmosphere filled with TNT dust 
for hours, but I do not recall even a slight headache 
or dizziness from such exposure. 

Toxic jaundice is the direct result of what may be 
termed " TNT liver." The yellow color of the skin 
caused by the internal action of the TNT persists 
long after the stain by external contact wears off. 
Furthermore, the color due to jaundice affects the entire 
body, while the mechanical staining colors only those 
parts which have been in contact with the TNT. 
About 33 per cent of the cases of toxic jaundice are 
fatal. 

6. Ancemia. This disease is the result of the action 
of TNT upon the erythrocytes or red blood corpuscles. 
These corpuscles are disintegrated, and the coloring 
matter is deposited in the kidneys and other organs, 
causing these organs to assume a dark brown or black 
color. As with toxic jaundice, not every person suffers 
the same effects. Some cases are on record where an 



118 TRINITROTOLUENE 

actual increase in the number of T, ed blood corpuscles 
has resulted from TNT poisoning. 

The summation of the research that has already 
been done on TNT poisoning indicates that the solu- 
tion of the problem consists more in prevention than 
in treatment. The steps to be taken in prevention, 
which have been suggested by the British Ministry of 
Munitions are: 

1. The employment of no persons under eighteen 
years of age without special permission. This insures 
the employment of none but mature men and women 
and lessens liability from carelessness or indifference. 

2. The rotation of work at two- week intervals; 
thus removing the employee from contact with the 
substance periodically. 

3. The use of masks, gloves, and clean-laundered 
overalls. 

4. Large and well-ventilated workrooms* 

5 r The furnishing to every employee of free milk 
and cocoa, and a weekly medical inspection. 

The wisdom of requiring the employees to drink 
milk has been severely questioned for this reason: 
Milk contains primarily fats and casein. The fats are 
capable of dissolving a large amount of TNT. There- 
fore, should any of the explosive accidentally find its 
way into the milk, or should there be any in the stomach 
through swallowing dust in the factory, this will dis- 
solve in the fats of the milk and will be absorbed by the 
blood. This action has been proved by Dr. Hay thorn, 
who has performed several experiments upon rabbits 
and guinea pigs with a solution of TNT in milk. 

The very least that can be said concerning the toxic 
action of TNT is that some persons are very susceptible 






TNT DISEASES 119 

to it. Minor poisonings should be treated as possible 
cases of severe poisonings until all doubt of the severe 
poisoning has been removed. A medical corps of 
sufficient size to afford constant medical supervision 
of the force of employees should be in constant attend- 
ance at the plant. In this way any slight poisoning 
or sickness will be checked before it has a chance to 
develop into a more serious form. 



REFERENCES 



CHAPTER II 



(1) Anallen, 77, 216. 

(2) " 155, 1-29. 

(3) " 54,9. 

(4) " 54, 12. 

(5) " 77,216. 

(6) " 76, 286. 

(7) " 77,216. 

(8) " 131,304. 

(9) " 77,216 

(10) " 44, 306. 

(11) Jahres Berichte, 22, 360. 

(12) Anallen, 155, 2. 

(13) " 128, 178. 

(14) Berichte Chem. Gesell., 3, 202. 

(15) Jahres Berichte, 22. 360. 

(16) Anallen, 172, 221 

(17) " 128,178. 

(18) Berichte, 16, 1596. 

(19) AnaUen, 215, 375. 

(20) Chem. Zentr. 1914, II, 762. 

(21) Atti. R. Accad. Lincei., 24, I, 888. 

(22) Marshall, " Explosives," 260-261. 

CHAPTER III 

(1) Proc. K. Accad. Metensch, Amsterdam, 1908, Vol. XI, 248. 

(2) Organic Chemistry (Holleman) Ed. 1910, 486. 

(3) Proc. K. Accad. Metensch, 1908, Vol. XI, 248. 

(4) Rec. trav. Chim., 27, 208. 

(5) Berichte, 18, 1336. 

(6) Chem. Zentr., 1914, II, 762. 

121 



122 REFERENCES 

(7) Annalen, 215, 344. 

(8) Berichte, 1913, 558. 

(9) Anallen, 217, 206. 
Anallen, 225, 384. 

(10) Berichte, 18, 306. 
Anallen, 44, 307. 

(11) Berichte, 1914, 707. 

(12) Anallen, 155, 1-29. 

(13) Anallen, 215, 344. 

(14) Gazz. Ital. China., 45 II, 32-44. 

CHAPTER IV 

(1) Journal Ind. and Eng. Chem., 8, 998. 

(2) Met. and Chem. Eng., 14, 467-8. 

(3) Chem. News, 112, 247. 

(4) J. Soc. Chem. Ind., 34, 781-2. 

(5) British Patent No. 23,181, Nov. 27, 1914. 

(6) British Patent No. 15,445, Nov. 2, 1915. 

(7) U. S. A. patent No. 1,149,585, Aug. 10, 1915 

(8) Ann. Inst. Agron. Moscow, 19, 56-9. 

(9) Z. ges. Schiess-Sprengstoff, 10, 109-11. 

CHAPTER V 

(1) U. S. A. patent, 1,225,321, May 8, 1917. 

(2) British patent, 7047, May 11, 1915. 

CHAPTER VI 

(1) Journal Amer. Chem. Soc, 39, 504-14. 

CHAPTER VII 

(1) J. Ind. and Eng. Chem., 1910, 103. 

(2) 1st Scienze Let., 46, 1913. 

(3) J. Soc. Chem. Ind., 1915, 60. 

(4) Anallen, 215, 344. 

(5) Anallen, 215, 370. 

(6) Berichte, 1914, 704. 

(7) Berichte, Vol. Ill, 217. 

(8) Trans. Lon. Chem. Soc, 79, 350. 

(9) Berichte, 34, 2842. 



REFERENCES 123 



(10) Trans. Lon. Chem. Soc', 1903, 527. 

(11) Mem. Poud. Saltpetres, 16, 40-51. 

CHAPTER VIII 

(1) Zeit. Phys. Chem., 57, 341. 

(2) J. Lon. Chem. Soc., 34, 60. 

(3) Berichte, 36, 4260. 

(4) Abst. Chem. Soc, 1907, 2076. 

(5) Atti. R. Accad. Lincei, 14, II, 199. 

(6) Trans. Lon. Chem. Soc, 1903, 1108. 

(7) Atti. R. Accad. Lincei, 14, II, 199. 

(8) Chem. Zeit., 30, 295. 

(9) Chem. News, 112, 283-4. 

(10) Berichte, 22, 2681. 

(11) Berichte, 21, 428. 

(12) Annalen, 215, 370. 

(13) Berichte, 40, 3324 et seq. 

(14) Rec. Trav. Chem., 14, 121-130. 

(15) Berichte, 32, 607. 

(16) Gazetta, 31, 133. 

(17) Zeitschr. Anorg. Chem., 69, 270. 

(18) Berichte, 43, 3417. 

(19) J. Russ. Chem. Soc, 30, 960. 



INDEX 



A 

PAGE 

Accidents 106 

Acidity in TNT, determination of 63 

Acids, table of 39 

Action of inorganic salts on MNT 100, 101 

of light on MNT 100 

of light on TNT 91 

of mineral matter on nitration 40 

of nascent hydrogen on nitration 40, 41 

Alkali carbonates, reaction with TNT 85, 86 

hydroxides, reaction with TNT 84 

Aluminium explosive 4 

Ammonium nitrate 47 

sulphide, reaction with TNT 86, 88 

Analysis of gases from the burning of TNT 90 

of gases from explosion of TNT 91 

of TNT 62 

Anaemia from TNT 117 

Aniline, reaction with TNT 82, 83 

Ash in TNT, determination of 64 

B 

Benzaldehyde, reaction with TNT 87 

Benzoen 6 

Binitrotropfol 24, 50 

Blending 45 

Blood, effect of TNT upon the 115 

Blow case 49 

125 



126 INDEX 

PAGH 

Boiling-point of the mononitrotoluenes 96 

Burning of TNT, reaction of 90 

C 

Cheddite 5 

Chemical control 34, 51 

properties of dinitrotoluenes 103 

of mononitrotoluenes 98 

of trinitrotoluenes 82 

Color of TNT 62 

Constituents of crude TNT 26 

Constitution of TNT 17 

Crystalline form of dinitrotoluenes 102 

of mononitrotoluenes 96 

of trinitrotoluenes 80 

Crystallization 45 

D 

Denitration of spent acid 47 

Density of TNT 94 

Detection of toluene in benzene 101 

Determination of para nitrotoluene 99 

Detonators 4 

Dimethylaniline, reaction with TNT 84 

Dinitrocresols 85 

Dinitrotoluenes, action of naphthalene upon 104 

and TNT, eutectic mixture 93 

chemical properties of 103 

crystalline form of 102 

history of 15 

melting-points of isomeric 102 

nitration of 21, 26, 27 

oxidation of 104 

preparation of various 103 

products of nitration of 27 

reduction of 104 

structural formulae of 102 



INDEX 127 

PAGE 

Dinitrotoluidoxides 86 

Diphenylamine test 65, 70 

Disease in TNT plants, prevention of 118 

Donarite 5 

Dracyl 8 



E 

Effect of breathing fumes from burning TNT 114 

of breathing fumes from nitration 116 

of heat on TNT 88 

of swallowing TNT 114 

of TNT on the blood 115 

of TNT on the skin 114, 116 

Exonitrotoluenes 105 

Explosion of TNT, reaction of 90 

Explosions 106 

Explosive tests on TNT 92 

Eutectic mixture of DNT and TNT 93 



F 

Factors affecting nitration 40 

yield 41 

Fineness of TNT, determination of 62 

Flaking 46 

Formation of DNT in first stage nitration 36 

of phenolic compounds in nitration 40 

of sulphonic compounds in nitration 41 

Fortification of spent acid, precautions 110 

Fumes from burning TNT, effect of 114 

from nitration, effect of 116 

G 

Gases from the explosion of TNT, constituents of 91 

Gassing 116 

German process of nitration 38 



128 INDEX 

PAGE 

Grainer 45 

Graining 45 

Guncotton, sensitiveness of 92 

H 

Heat, effect of, on TNT 88 

Heavy metals in TNT 72 

Hydrogen, nascent, in nitration 40 

I 

Ideal nitration , 22 

Impurities in TNT 52 

Insoluble residue in TNT, determination of 63 

Isomerism of the nitrotoluenes 12 

J 

Jaundice 117 

L 

Labyrinth 45 

Langenscheidt process of nitration 35 

Light, action of, on mononitro toluenes 100 

on trinitrotoluenes 91 

M 

Macarite 5 

Melting-point of dinitrotoluenes 102 

of mononitrotoluenes 96 

of trinitrotoluenes 80 

of TNT, determination of 66, 71 

Meta nitrotoluene 13, 23, 24 

Mineral matter in nitration 40 

Moisture in TNT, determination of 62 

Mononitrotoluenes, action of inorganic salts on 100 

of light on 100 

of potassium ferricyanide on 98 

of sodium hydroxide on 101 



INDEX 129 



PAGE 



Mononitrotoluenes, boiling-points of isomeric 96 

chemical properties of 98 

crystalline form of 96 

effect of temperature on formation of 23 

history of 9 

melting-points of isomeric 96 

nitration of 21, 25 

oxidation of 98 

preparation of isomeric 96 

products of the nitration of 25 

reduction of 99 

separation of 97 

specific gravity of 96 

structural formula? of 95 



N 

Naphthalene reaction with dinitro toluenes 104 

with trinitrotoluenes 85 

Naphthylamine, reaction with TNT 87 

Nitration, factors affecting 40 

formation of DTN in first stage of 36 

formation of phenolic compounds in 40 

formation of sul phonic compounds in 41 

ideal 22 

Langenscheidt process of 35 

one-stage process of 33 

three-stage process of 37 

two-stage process of 34 

Nitrator 29 





One-stage process of nitration 33 

Orthonitrotoluene, test for 99 

Oxidation of dinitrotoluenes 104 

of trinitrotoluenes 88 



130 INDEX 

P 

PAGE 

Packing 61 

Para nitrotoluene, determination of 99 

Permonite 4 

Phenolic compounds in nitration ■. 40 

Phenylnitromethanes 104 

Picric acid 3 

disadvantages of 3 

sensitiveness of 92 

Piperidine reaction with TNT 87 

Plasteryl 4 

Poisoning from TNT 112 

Potassium ferricyanide reaction with MNT 98 

Precautions in fortifying acids 110 

Preparation of dinitrotoluenes 103 

of mononitrotoluenes 96 

of trinitrotoluenes 81 

Prevention of TNT diseases 118 

Products of nitration of dinitrotoluenes 27 

of mononitrotoluenes 25 

Purification of trinitrotoluene by alcohol 53 

by carbon tetrachloride mixture 55 

by mechanical means 57 

by sodium sulphite 56 

by sulphuric acid 54, 58 

R 

Rash, TNT 116 

Reaction of burning of TNT 90 

of explosion of TNT 90 

Reduction of dinitrotoluene 104 

of mononitrotoluene 99 

Retinaptha 6 

Rules for health in munition plants 118 

S 

Screening 46 

Separation of mononitrotoluenes 97 



INDEX 131 

PAGE 

Shock, sensitiveness to, of guncotton 92 

of picric acid 92 

of TNT... 92 

Skin, effect of TNT on 114, 116 

Sodium salts of TNT 44, 57, 84 

Solidifying point of TNT, determination of 68 

Solubilities of TNT 81 

Solvent recovery, stills for 60 

Specific gravity of mononitrotoluenes 96 

Spent acid, analysis of 46 

denitration of 47 

effect of, on TNT 41 

separation of TNT from 47 

utilization of 48 

Stability tests 69 

Stilbene derivatives 87 

Structural formulae of dinitrotoluenes 102 

of mononitrotoluenes 95 

of trinitrotoluenes 78 

Sulphonation theory 21 

Sulphonic acids, formation of 41 



Test explosive 76 

for orthonitro toluene 99 

for toluene in benzene 101 

Trauzl lead block 73 

Webster's 113 

1 etranitromethane 40 

Theory of nitration, German 27 

Italian 27 

of sulphonation 21 

Three-stage process of nitration 37 

Thunderite 4 

TNT anaemia 117 

TNT jaundice 117 

TNT rash , 116 



132 INDEX 

PAGE 

Toluene detection of, in benzene 101 

from balsam of tolu 6 

from coal tar 8 

from crude wood alcohol 8 

from dragon's blood 7 

from p'ne resin 6 

history of 6, 7, 8 

nitration of 20 

specifications for 32 

synthetic 9 

Trauzl lead block test 73 

Trinitrobenzoic acids 40 

Trinitrotoluene, action of light on 91 

analysis of 62 

and DNT, eutectic mixture of 93 

blending of 45 

constitution of 17 

crystalline form of 80 

crystallization of 45 

density of 94 

effect of breathing fumes from burning 114 

of breathing fumes from nitration of 116 

on the blood of 115 

on the skin of 1 14, 1 16 

on the system of 115 

flaking 46 

gases from burning 90 

gases from explosion of 91 

graining of 45 

history of 17 

inspection of 61 

melting-points of isomeric 80 

packing of 61 

poisoning from 112 

preparation of isomeric 81 

purification of 52 

reaction of 82 

screening of ,,,,,,,,, 46 



INDEX 133 

PAGE 

Trinitrotoluene, sensitiveness of 92 

separation of from spent acid 42 

solubility of 81 

structural formulae of 78 

washing of 43 

U 

Utilization of spent acids 48 

W 

Washing of TNT 43 

Webster's test , 113 

Y 

Yield, factors affecting 41 






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FERNBACH, R. L. Chemical Aspects of Silk Manu- 
facture. 121110. cloth. 84 pp. net, $1.00 

Glue and Gelatine. A practical treatise on the 

methods of testing- and use. Illustrated. 8vo. cloth. 
208 pp. net, $3.00 

FIRTH, J. B. Practical Physical Chemistry. 111. 5 x 7. 
cloth. 189 pp. net, $1.00 

FISCHER, E. Introduction to the Preparation of Or- 
ganic Compounds. Translated from the new (eighth) 
German edition by R. V. Stanford. Illustrated. 
121110. cloth. 194 pp. net, $1.25 

F0YE, J. C. Chemical Problems. Fourth Edition, revised 
and enlarged. i6mo. cloth. 145 pp. (Van Nos- 
trand Science Series, No. 69.) $0.50 

FRANZEN, H. Exercises in Gas Analysis. Translated 



6 D. VAN NO ST RAND COMPANY'S 

from the first German edition, with corrections and 
additions by the author, by Thomas Callan. 30 dia- 
grams. 5x7*4- cloth. 127 pp. net, $1.00 

FRITSCH, J. The Manufacture of Chemical Manures. 

Translated from the French, with numerous notes, by 
Donald Grant. 69 illus., 108 tables. Svo. cloth. 
355 PP- net, $4.00 

GROSSMANN, J. Ammonia and Its Compounds. Illus- 
trated. i2mo. cloth. 151 pp. net, $1.25 

HALE, WILLIAM J. Calculations in General Chemistry. 
With definitions, explanations and problems. Fifth 
Edition, revised. i2mo. cloth. 185 pp. net, $1.00 

HALL, CLARE H. Chemistry of Paints and Paint Ve- 
hicles. 8vo. cloth. 141 pp. net, $2.00 

HERING, C, and GETMAN, F. H. Standard Tables of 
Electrochemical Equivalents and Their Derivatives. 
Illustrated. 4/2x7/2. cloth. 140 pp. net, $2.00 

HILDITCH, T. P. A Concise History of Chemistry. 
16 diagrams. i2mo. cloth. 273 pp. net, $1.25 

HILL, C. W. Laboratory Manual and Notes in Beginning 
Chemistry. Second Revised Edition. In Press 

H0YT, W. F. Chemistry by Experimentation, Including 
Qualitative Analysis. A laboratory manual for the 
first year course. In Press 

HtiBNER, JULIUS. Bleaching and Dyeing of Vegetable 
Fibrous Materials. 95 illus. (many in two colors). 
Svo. cloth. 457 pp. net, $5.00 

HUDSON, 0. F. Iron and Steel. An introductory text- 
book for engineers and metallurgists. With a section 
on Corrosion by Guv D. Bengough.. 47 illus. 8vo. 
cloth. 184 pp.' net, $2.00 

HURST, GEO. H. Lubricating Oils, Fats and Greases. 
Their origin, preparation, properties^ uses, and analy- 
sis. Third Edition, revised and enlarged, by Henry 
Leask. 74 illus. 8vo. cloth. 405 p. net, $4.00 



LIST OF CHEMICAL BOOKS 



HURST, G. H., and SIMMONS, W. H. Textile Soaps and 
Oils. Second Edition, revised and partly rewritten. 
ii illustrations. 5^x8^. 204 pp. net, $3.00 

HYDE, FREDERIC S. Solvents, Oils, Gums, Waxes and 
Allied Substances. 514x8^. cloth. 182 pp. net, $2.00 

INGLE, HERBERT. Manual of Agricultural Chemistry. 
Illustrated. 8vo. cloth. 388 pp. net, $3.00 

JOHNSTON, J, F. W. Elements of Agricultural Chem- 
istry. Revised and lewritten by Charles A. Cameron 
and C. M. Aikman. Nineteenth Edition. Illustrated. 
121110. cloth. 502 pp. $2.60 

JONES, HARRY C. A New Era in Chemistry. Some of 
the mere important developments in general chemis- 
try during the last quarter of a century. Illustrated. 
121-no. cloth. 336 pp. net, $2.00 

The Nature of Solution. Edited by E. E. Reid. 

Illustrated. 6 x 9. cloth. 406 pp. net,$3.50 

KEMBLE. W. F., and UNDERHILL, C. R. The Periodic 
Law and the Hydrogen Spectrum. Illustrated. 8vo. 
paper. 16 pp. net, $0.50 

KERSHAW, J. B. C. Fuel, Water, and Gas Analysis, for 
Steam Users. 50 ill. 8vo. cloth. 178 pp. net, $2.50 

Electro-Thermal Methods of Iron and Steel Produc- 
tion. With an introduction by Dr. J. A. Fleming, 
F.R.S. 50 tables, 92 illustrations. 5J^x8j4- cloth. 
262 pp. net, $3.00 

KNOX, JOSEPH. Physico-chemical Calculations. i2mo. 
cloth. 196 pp. net, $1.00 

The Fixation of Atmospheric Nitrogen. Illustrated. 

5x7^. cloth. 120 pp. (Van Nostrand's Chemical 
Monographs.) net, $0.75 

K0LLER, T. Cosmetics. A handbook of the manufac- 
ture, employment and testing of all cosmetic materials 
and cosmetic specialties. Translated from the German 
by Charles Salter. 8vo. cloth. 262 pp. net, $2.50 



D. VAN MOST RAND COMPANY'S 



Utilization of Waste Products. A treatise on the 

rational utilization, recovery and treatment of waste 
products of all kinds. Second Revised and Enlarged 
Edition. 22 illustrations. 5^4x8^4. cloth. 336 pp. 

net, $3.00 

KOPPE, S. W. Glycerine. Its introduction,, uses and 
examination. For chemists, perfumers, soapmakers, 
pharmacists, and explosives technologists. 7 illustra- 
tions. 534 x ?y 2 . 260 pp. $2.50 

KREMANN, R. The Application of Physico-chemical 
Theory to Technical Processes and Manufacturing 1 
Methods. Authorized translation by Harold E. Potts, 
M.Sc. 35 diagrams. 8vo. cloth. 215 pp. net, $2.50 

KRETSCHMAFv, KARL. Yarn and Warp Sizing in All 
Its Branches. Translated from the German by C. 
Salter. 122 illus. 8vo. cloth. 192 pp. net, $4.00 

LAMB0RN, L. L. Modern Soaps, Candles and Glycerin. 
224 illustrations. 8vo. cloth. 700 pp. net. $7.50 

Cotton Seed Products. 79 illus. 8vo. cloth. 253 pp. I 

net, $3.00 

LASSAR C0HN. Introduction to Modern Scientific 
Chemistry. In the form of popular lectures suited for 
University Extension students and general readers. 
Translated from the Second German Edition by M. M. I 
Pattison Muir. Illus. i2mo. cloth. 356 pp. $2.00 

LETTS, E. A. Some Fundamental Problems in Chemis- 
try: Old and New. 44 illustrations. 8vo. cloth. 236 J 
pp. net, $2.00 

LLOYD, STRAUSS L. Fertilizer Materials. In Press 

LUNGE, GEORGE. Technical Methods of Chemical 
Analysis. Translated from the Second German Edition 
by Charles A. Keane, with the collaboration of eminent 
experts. Complete in three volumes. Six parts. 448 
illustrations. 6y 2 ^9 l />. cloth. 3494 pp. net, $48.00 



LIST Or CHEMICAL BOOKS 



Vol. I. (in two parts). 201 illustrations. 6^x9^2 
cloth. 1024 pp. net. $15.00 

Vol. II. (in two parts). 149 illustrations. 6^x9^. 
cloth. 1294 pp. net, $18.00 

Vol. III. (in two parts). 98 illustrations. 6 l / 2 xg-j. 
cloth. 1174 pp. net. $18.00 

— Technical Chemists' Handbook. Tables and meth- 
ods of analysis for manufacturers of inorganic chemi- 
cal products. Second Edition, revised. Illus. 121110. 
leather. 276 pp. net, $3.50 

— Coal, Tar and Ammonia. Fifth and Enlarged Edi- 



tion. In three volumes, not sold separately. 111. 6x9. 

cloth. 1600 pp. net, $18.00 

— The Manufacture of Sulphuric Acid and Alkali. 

A theoretical and practical treatise. 

Vol." I. Sulpluiric Acid. Fourth Edition, enlarged. 

In three parts, not sold separately. 543 illustrations. 

8vo. cloth. 1665 pp. net. $18.00 
Sulphuric and Nitric Acid. Supplement to Vol. f. 



Fourth Edition. Illustrated. 6x9. cloth. 347 pp. 

net, $5.00 
Vol. II. Sulphate of Soda, Hydrochloric Acid, Leblanc 
Soda. Third Edition, much enlarged. In two parts, 
not sold separately. 335 illustrations. 8vo. cloth. 
1044 PP- net, $15.00 
Vol. III. Ammonia Soda. Various Processes of Al- 
kali-making, and the Chlorine Industry. 181 illus- 
trations. 8vo. cloth. 784 pp. net. $10.00 
Vol. IV. Electrolytical Methods. In Press. 
Technical Gas Analysis. 143 illustrations. 6x9. 



cloth. 422 pp. net, $4.00 

McINTOSH, JOHN G. The Technology of Sugar. Third 

Edition, revised and enlarged. 244 illustrations. 

6x8^. 540 pp. $5.00 

McINTOSH, JOHN G. The Manufacture of Varnish and 



io D. VAN NOSTRANl) COMPANY'S 

Kindred Industries. Illus. 8vo. cloth. In 3 volumes. 
Vol. I. Oil Crushing, Refining and Boiling ; Manu- 
facture of Linoleum ; Printing and Lithographic Inks ; 
India Rubber Substitutes. 29 illus. 160 pp. net, $3.50 
Vol. II. Varnish Materials and Oil Varnish Making. 
66 illus. 216 pp. net, $4.00 

Vol. III. Spirit Varnishes and Varnish Materials. 
64 illus. 492 pp. net, $4.50 

MARTIN, G. Triumphs and Wonders of Modern Chem- 
istry. A popular treatise on modern chemistry and 
its marvels written in non-technical language. 76 il- 
lustrations. i2mo. cloth. 358 pp. net, $2.00 

■ Modern Chemistry and Its Wonders. A popular 

account of some of the more remarkable recent ad- 
vances in chemical science. 65 illustrations. 5J4 x 7^4. 
267 pp. $2.00 

MELICK, CHARLES W. Dairy Laboratory Guide. 52 
illustrations. i2mo. cloth. 135 pp. net, $1.25 

MERCK, E. Chemical Reagents : Their Purity and Tests. 
Second Edition, revised. 6x9. cloth. 210 pp. $1.00 

MIERZINSKI, S. The Waterproofing of Fabrics. Trans- 
lated from the German by A. Morris and H. Robson. 
Second Edition, revised and enlarged. 29 illustrations. 
5 x yy 2 . 140 pp. net, $2.50 

MITCHELL, C. A. Mineral and Aerated Waters, tit 
illustrations. 8vo. cloth. 244 pp. net, $3.00 

MITCHELL, C A., and PRLDEAUX, R. M. Fibres Used 
in Textile and Allied Industries. 66 illustrations. 
8vo. cloth. 208 pp. net, $3.00 

MUNBY, A E. Introduction to the Chemistry and 
Physics of Building Materials. Illus. 8vo. cloth. 365 
pp. (VanNtostrand's Westminster Series.) net, $2.00 

MURRAY, J. A. Soils and Manures. 33 illustrations. 
8vo. cloth. 367 pp. (Van Nostrand's Westminster 
Series.) net, $2.00 



LIST OF CHEMICAL BOOKS n 

NEAVE, G. B.. and HEILBRON, I. M. The Identifica- 
tion of Organic Compounds. i2mo. cloth, in pp. 

net, $1.25 

NORTH, H. B. Laboratory Experiments in General 
Chemistry. Second Edition, revised. 36 illustrations. 
5 4 x 724- cloth. 212 pp. net, $1.00 

OLSEN, J. C. A Textbook of Quantitative Chemical 
Analysis by Gravimetric and Gasometric Methods. 
Including 74 laboratory exercises giving the analysis 
of pure salts, alloys, minerals and technical products. 
Fifth Edition, revised and enlarged. Illustrated. 
6^x914. cloth. 576 pp. net, $3.50 

PARRY, ERNEST J. The Chemistry of Essential Oils 
and Artificial Perfumes. Second Edition, thoroughly 
revised and greatly enlarged. Illustrated. 8vo. cloth. 
554 pp. net, $5.00 

Food and Drugs. In 2 volumes. Illus. 8vo. cloth. 

Vol. I. The Analysis of Food and Drugs (Chemical 
and Microscopical). 59 illus. 724 pp. net, $7.50 

Vol. II. The Sale of Food and Drugs Acts, 1873- 
1907. 184 pp. net, $3.00 

PARTINGTON, JAMES R. A Text-book of Thermo- 
dynamics (with special reference to Chemistry). 91 
diagrams. 8vo. cloth. 550 pp. net, $4.00 

■ Higher Mathematics for Chemical Students. 44 

diagrams. i2mo. cloth. 272 pp. net, $2.00 

PERKIN, F. M., and JAGGERS. E. M. Textbook of Ele- 
mentary Chemistry, yy illustrations. 4^4 x 7. cloth. 
342 pp. net, $1.00 

PLATTNER'S Manual of Qualitative aud Quantitative 
Analysis with the Blowpipe. Eighth Edition, revised. 
Translated by Henry B. Cornwall, assisted by John 
H. Caswell, from the Sixth German Edition, by Fried- 
rich Kolbeck. 87 ill. 8vo. cloth. 463 pp. net, $4.00 



12 D. WAN NOSTRAND COMPANY'S 

POLLEYN, F. Dressings and Finishings for Textile 
Fabrics and Their Application. Translated from the 
Third German Edition by Chas. Salter. 60 illustra- 
tions. 8vo. cloth. 279 pp. net, $3.00 

POPE, F. G. Modern Research in Organic Chemistry. 
20i diagrams. 121110. cloth. 336 pp. net, $2.25 

POPvRITT, B. D. The Chemistry of Rubber. 5 x 7)4. 
cloth. 100 pp. (Van Nostrand's Chemical Mono- 
graphs.) net, $0.75 

POTTS, HAROLD E. Chemistry of the Rubber Industry. 
8vo. cloth. 163 pp. net, $2.00 

PRESCOTT, A. B. Organic Analysis. A manual of the 
descriptive and analytical chemistry of certain carbon 
compounds in common use. Sixth Edition. Illus- 
trated. 8vo. cloth. 533 pp. $5.00 

PRESCOTT, A. B., and JOHNSON, 0. C. Qualitative 
Chemical Analysis. Seventh Edition, revised and en- 
larged by John C. Olsen. A.M., Ph.D. 6^x9/2. 
cloth. 440 pp. net, $3.50 

PRESCOTT, A. B., and SULLIVAN, E C. First Book in 
Qualitative Chemistry. For studies of water solution 
and mass action. Eleventh Edition, entirely rezvritten. 
i2mo. cloth. 150 pp. net, $1.50 

PRIDEATJX, E. B. R. Problems in Physical Chemistry 
with Practical Applications. 13 diagrams. 8vo. cloth. 
323 pp. net, $2.00 

ELCHARDS, W. A., and NORTH, H. B. A Manual of 
Cement Testing. For the use of engineers and chem- 
ists in colleges and in the field. 56 illustrations. 
i2mo. cloth. 147 pp. net, $1.50 

RlilEAL, S. Glue and Glue Testing. Second Edition, 
revised and enlarged. 14 illustrations. sH x ^H- 
cloth. 194 pp. net, $4.00 



LIST OF CHEMICAL BOOKS 13 

ROGERS, ALLEN (Editor). Industrial Chemistry. A 
manual for the student and manufacturer. Second 
Edition, thoroughly revised and enlarged. Written 
by a staff of eminent specialists. 304 illustrations. 
6^x9^4. cloth. 1026 pp. net, $5.00 

ROGERS, ALLEN. Elements of Industrial Chemistry. 
An abridgement of The Manual of Industrial Chem- 
istry. 117 illustrations, 1 folding plate. 5^x8. 
521 pp. net, $3.00 

A Laboratory Guide of Industrial Chemistry. Illus- 
trated. 8vo. cloth. 170 pp. net, $1.50 

R0HLAND, PAUL. The Colloidal and Crystalloidal State 
of Matter. Translated by W. J. Britland and H. E. 
Potts. i2mo. cloth. 54 pp. net, $1.25 

ROTH, W. A. Exercises in Physical Chemistry. Author- 
ized translation by A. T. Cameron. 49 illustrations. 
8vo. cloth. 208 pp. net, $2.00 

SCHERER, R. Casein : Its Preparation and Technical 
Utilization. Translated from the German by Charles 
Salter. Second Edition, revised and enlarged. Il- 
lustrated. 8vo. cloth. 196 pp. net, $3.00 

SCHIDROWITZ, P. Rubber. Its Production and Indus- 
trial Uses. Plates, 83 illus. 8vo. cloth. 320 pp. 

net, $5.00 

SCHWEIZER, V. Distillation of Resins, Resinate Lakes 
and Pigments. Illustrated. 8vo. cloth. 183pp.net, $3.50 

SCOTT, W. W. Qualitative Chemical Analysis. A labo- 
ratory manual. Second Edition, thoroughly revised. 
Illus. 8vo. cloth. 180 pp. net. $1.50 

SCOTT, W. W. (Editor). Standard Methods of Chemical 
Analysis. 111. 6x9. 900 pp. net, $6.00 

SCUDDER, HEYWARD. Electrical Conductivity and 
Ionization Constants of Organic Compounds. 6x9. 
cloth. 575 pp. net, $3.00 



14 D. J 'AN NOSTRAND COMPANY'S 

SEARLE, ALFRED B. Modern Briekmaking. 260 illus- 
trations. 8vo. cloth. 449 pp. net, $5.00 

Cement, Concrete and Bricks. 113 illustrations. 

5^x8^4. cloth. 415 pp. net, $3.00 

SEIDELL, A. Solubilities of Inorganic and Organic Sub- 
stances. A handbook of the most reliable quantitative 
solubility determinations. Second Printing, corrected. 
8vo. cloth. 367 pp. net, $3.00 

SENTER, G. Outlines of Physical Chemistry. Second 
Edition, revised. Illus. i2mo. cloth. 401 pp. $1.75 

A Text-book of Inorganic Chemistry. 90 illustra- 
tions. i2mo. cloth. 595 pp. net, $1.75 

SEXTON, A. H. Fuel and Refractory Materials. Second 
Ed., revised. 104 illus. 121110. cloth. 374 pp. net, $2.00 

Chemistry of the Materials of Engineering. Illus. 

121110. cloth. 344 pp. net, $2.50 

SIMMONS. W. H., and MITCHELL, C. A. Edible Fats 
and Oils. Their composition, manufacture and analy- 
sis. Illustrated. 8vo. cloth. 164 pp. net, $3.00 

SINDALL. R. W. The Manufacture of Paper. 58 illus. 
8vo. cloth. 285 pp . (Van Nostrand's Westminster 
Series.) net, $2.00 

SINDALL, R. W., and BACON, W. N. The Testing of 
Wood Pulp. A practical handbook for the pulp and 
paper trades. Illus. 8vo. cloth. 150 pp. net, $2.50 

SMITH, J. C. The Manufacture of Paint. A manual for 
paint manufacturers, merchants and painters. Second 
Edition, revised and enlarged. 80 illustrations $y 2 x 
8^4. cloth. 286 pp. net, $3.50 

SMITH, W. The Chemistry of Hat Manufacturing. 
Revised and edited by Albert Shonk. Illustrated. 
i2mo. cloth. 132 pp. net, $3.00 

S0UTHC0MBE, J. E. Chemistry of the Oil Industries. 
Illus. 8vo. cloth. 209 pp. net. $3.00 



LIST OF CHEMICAL BOOKS 15 

SPEYERS, C. L. Text-book of Physical Chemistry. 20 

illustrations. 8vo. cloth. 230 pp. net, $2.25 

SPIEGEL, L. Chemical Constitution and Physiological 

Action. Translated by C. Luedeking and A. C. 

Boylston. 5x7/2. cloth. 160 pp. net, $1.25 

STEVENS, H. P. Paper Mill Chemist. 67 illustrations. 

82 tables. i6mo. cloth. 280 pp. net, $2.50 

SUDB0R0UGH, J. J., and JAMES, J. C. Practical Or- 
ganic Chemistry. 92 illustrations. i2mo. cloth. 

394 pp. net, $2.00 

TERRY, H. L. India Rubber and Its Manufacture. 

18 illustrations. 8vo. cloth. 303 pp. (Van Nos- 

trand's Westminster Series.) net, $2.00 

TITHERLEY, A. W. Laboratory Course of Organic 

Chemistry, Including Qualitative Organic Analysis. 

Illustrated. 8vo. cloth. 235 pp. net, $2.00 

TOCH, M. Chemistry and Technology of Paints. Second 

Edition, revised and enlarged. 111. 6x9. 373 pp. 

net, $4.00 
TOCH, M. Materials for Permanent Painting. A manual 

for manufacturers, art dealers, artists, and collectors. 

With full-page plates. Illustrated. i2mo. cloth. 

208 pp. net, $2.00 

TUCKER, J. H. A Manual of Sugar Analysis. Sixth 

Edition. 43 illustrations. 8vo. cloth. 353 pp. $3.50 
UNDERWOOD, N., and SULLIVAN, T. V. Chemistry and 

Technology of Printing Inks. 9 illustrations. 6 x 0. 

cloth. 145 pp. net. $3.00 

VAN N0STRANDS Chemical Annual. Edited by John 

C. Olsen and Alfred Melhado. A handbook of useful 

data for analytical manufacturing and investigating 

chemists and chemical students. Third Issue, enlarged. 

5x7^. leather. 683 pp. net, $2.50 

VINCENT, C. Ammonia and Its Compounds. Their 



l6 D. VAN NOSTRAND COMPANY'S 

manufacture and uses. Translated from the French 
by M. J. Salter. 32 ill. 8vo. cloth. 113 pp. net, $2.00 

VON GEORGIEVICS, G. Chemical Technology of Textile 
Fibres. Translated from the German by Charles 
Salter. 47 illustrations. 8vo. cloth. 320 pp. net, $4.50 

Chemistry of Dyestuffs. Translated from the Sec- 
ond German Edition by Charles Salter. 8vo. cloth. 
412 pp. net, $4.50 

VOSMAER, A. Ozone, Its Manufacture. Properties and 
Uses. 75 illustrations. 6 x 9. cloth. 210 pp. net, $2.50 

WADM0RE, J. M. Elementary Chemical Theory. Illus. 
121110. cloth. 286 pp. net, $1.50 

WALKER, JAMES. Organic Chemistry for Students of 
Medicine. Illus. 6x9. cloth. 328 pp. net, $2.50 

WALSH. J. J. Mining and Mine Ventilation. 26 illus 
8vo. cloth. 192 pp. net, $2.00 

WARNES, A. R. Coal Tar Distillation and Working Up 
of Tar Products. 67 illustrations. 5^x8^. cloth. 
197 pp. net, $2.50 

WHITE, C. H. Methods in Metallurgical Analysis. 106 
illustrations. 5x7^. cloth. 365 pp. net, $2.50 

WHITE. G. F. A Laboratory and Class-room Guide to 
Qualitative Chemical Analysis. 5x7. cloth. 178 pp. 

net, $1.25 

WILSON, F. J., and HEILBR0N, I. M. Chemical Theory 
and Calculations. An elementary text-book. Illus., 3 
folding plates. 121110. cloth. 145 pp. net, $1.00 

WOOD, J. K. The Chemistry of Dyeing. 5 x yy 2 . cloth. 
Sy pp. ( Van Nostrand's Chemical Monographs.) 

net, $0.75 

W0RDEN, E. C. The Nitrocellulose Industry. A com- 



LIST OF CHEMICAL BOOKS 



pendium of the history, chemistry, manufacture, com- 
mercial application, and analysis of nitrates, acetates, 
and xanthates of cellulose as applied to the peaceful 
arts. With a chapter on gun cotton, smokeless pow- 
der and explosive cellulose nitrates. Illustrated. 
8vo. cloth. Two volumes. 1239 PP- net, $10.00 

Technology of Cellulose Esters. A theoretical and 

practical treatise on the origin, history, chemistry, man- 
ufacture, technical application and analysis of the pro- 
ducts of acylation and alkylation of normal and modi- 
fied cellulose, including nitrocellulose, celluloid, pyr- 
oxylin, collodion, celloidin, gun-cotton, acetycellulose 
and viscose, as applied to technology, pharmacy, 
microscopy, medicine, photography and the warlike 
and peaceful arts. In ten volumes. 600 ill., 12 plates, 
110,000 patent and literature references to the work 
of 12,000 investigators. 

Vol. VIII. Carbohydrate Carboxylates (Cellulose Ace- 
tate). Illustrated. 6/2x9^. 515pp. net, $5.00 
(Other volumes to follow at short intervals.) 
WEEN, HENRY. Organometallic Compounds of Zinc and 

Magnesium. 5x73^. cloth. 108 pp. (Van Nos- 
trand's Chemical Monographs.) net, $0.75 



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